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Purpose Intolerance is the most common reason for kinase inhibitor (KI) discontinuation in CLL. Umbralisib a novel, highly selective PI3Kδ/CK1e inhibitor, is active and well tolerated in CLL patients. This phase 2 trial evaluated umbralisib in CLL patients who are intolerant to prior BTK or PI3K inhibitor therapy. Patients and methods In this phase 2 trial (NCT02742090), umbralisib was initiated at 800 mg oral daily in CLL patients requiring therapy per investigator discretion who were intolerant to prior BTK or PI3K inhibitor therapy, until progression or toxicity. Primary endpoint was progression-free survival (PFS). Secondary endpoints included time to treatment failure and umbralisib safety profile. DNA isolated from buccal swabs was genotyped for polymorphisms in CYP3A4, CYP3A5 and CYP2D6. Results Fifty-one patients were enrolled (44 BTKi and 7 PI3Kδi intolerant). Median age was 70 years (range 48-96), median of 2 prior lines of therapy (1-7), 24% had del17p and/or TP53 mutation, and 65% were IGHV unmutated. Most common AEs leading to prior KI discontinuation were rash (27%), arthralgia (18%), and atrial fibrillation (16%). Median progression free survival (PFS) was 23.5 months (95% CI 13.1-not estimable). 58% of patients were on umbralisib for a longer duration than prior KI. Most common (≥5%) grade ≥3 AEs on umbralisib (all causality) were neutropenia (18%), leukocytosis (14%), thrombocytopenia (12%), pneumonia (12%), and diarrhea (8%). Six patients (12%) discontinued umbralisib due to an AE. Eight patients (16%) had dose reductions and were successfully re-challenged. Conclusions Umbralisib is safe and effective in this BTK and alternate PI3K inhibitor intolerant CLL population. These are the first prospective data to confirm that switching from a BTK or alternate PI3K inhibitor to umbralisib can result in durable, well tolerated responses.

Introduction: Venetoclax has demonstrated deep responses and sustained progression-free survival and is well tolerated in patients (pts) with previously untreated or relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic leukemia (CLL/SLL) in clinical trials. Some early studies provided initial insight of venetoclax utilization in the real-world (RW), but RW evidence focusing on venetoclax effectiveness and safety is still limited. This study assessed venetoclax effectiveness, safety, and treatment patterns in CLL pts treated in clinical practice. Methods: The CLL Collaborative Study of Real-World Evidence (CORE), a large multicenter chart review across 21 institutions in 4 countries, enrolled adult pts who initiated a first line (1L) therapy on/after 01/01/2012 or a new line of therapy (LOT) for R/R CLL/SLL on/after 02/12/2014 (current data cut through 06/08/2020). Clinical responses were abstracted from the medical records as assessed by treating physicians or investigators (iwCLL criteria were provided as reference). Overall response rate (ORR) was calculated as the proportion of pts with complete response (CR) or partial response (PR) out of pts with documented response assessments. Treatment patterns included choice of regimens and sequences, dose interruption, dose reduction, and discontinuation. Treatment discontinuation was defined as ending therapy for any reason(s) other than the completion of planned duration of therapy. Interruption was defined as a gap in the same LOT. All analyses were descriptive. Results: Of the 1231 CLL pts in the CORE data, 155 received venetoclax (21 in 1L and 134 in R/R) and were included in this study. Most of the sample were male (65%) and the median age at venetoclax initiation was 67.5 (range 37-91). For high-risk features among pts with available data, 33% (43/132 pts) had del(17p) or TP53 mutation, 24% (31/131 pts) had complex karyotype (≥ 3 abnormalities), and 77% (61/79 pts) had unmutated IGHV. At venetoclax initiation, 46%, 40%, and 14% of 151 pts with available data had low, medium, and high tumor burden, respectively. Median follow-up time from venetoclax initiation across all lines was 7.0 (0.1-43.1) months. Median number of prior LOT for R/R pts was 2 (1-5); the largest proportion of pts (36%) received venetoclax in 2L followed by 3L (26%). In 1L, venetoclax was most frequently used (62%) in combination (Figure 1), while in R/R setting venetoclax monotherapy was more commonly used (61%) followed by venetoclax + rituximab (25%; Figure 2). Majority of R/R pts (63%) received Bruton's tyrosine kinase inhibitors (BTKi) prior to venetoclax (Figure 2). Response was assessed and documented for 114 pts (74%). Among these, ORR was 75% (CR=40%, PR=35%) overall. Pts ≥65 years old had an ORR of 79% (CR=41%, PR=38%, n=74), and pts Overall, 48% of pts had adverse events (AEs) recorded. Five R/R pts (3.2%) had TLS events (defined by Howard or Cairo-Bishop criteria), of which 3 (1.9%) were clinical. Of the 5 pts, 2 had high tumor burden, and 3 had medium burden. Other AEs of interest include neutropenia (17%), thrombocytopenia (9%), and diarrhea/colitis (5%). Overall, 32% of pts discontinued venetoclax; 13% of all pts discontinued venetoclax due to AEs (primarily neutropenia [n=2] and thrombocytopenia [n=2]), followed by disease progression (8%). Venetoclax interruption rate was 14%, and dose reduction rate was 22% overall. Conclusions: Consistent with trial experiences, venetoclax demonstrates high response rates, including high-risk groups, and a manageable safety profile with low rates of TLS in clinical practice. Despite limitations of RW research, this study provides useful insights into treatment practices with venetoclax. Future research with longer follow-up is warranted to better understand the long-term clinical outcomes associated with venetoclax regimens. Disclosures Zheng: AbbVie: Current Employment. Sail:AbbVie Inc.: Current Employment, Current equity holder in publicly-traded company. Roeker:Abbott Laboratories: Other: spouse with minority ownership interest ; American Society of Hematology: Research Funding; AbbVie: Other: spouse with minority ownership interest . Manzoor:AbbVie: Current equity holder in publicly-traded company. Tuncer:AbbVie: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees. Allan:Abbvie, Janssen, AstraZeneca, Pharmacyclics: Honoraria; Celgene, Genentech, Janssen, TG Therapeutics: Research Funding; Acerta, Genentech, Abbvie, Sunesis, Ascentage, Pharmacyclics, Janssen, AstraZeneca, BeiGene: Consultancy. Ujjani:Gilead/Kite: Consultancy, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria; MorphoSys: Consultancy; Atara: Consultancy, Honoraria; Verastem Oncology: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding. Barr:Genentech: Consultancy; Merck: Consultancy; Abbvie/Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy; Celgene: Consultancy; Seattle Genetics: Consultancy; Verastem: Consultancy; TG therapeutics: Consultancy, Research Funding; Morphosys: Consultancy; Gilead: Consultancy; AstraZeneca: Consultancy, Research Funding. Brown:Novartis: Consultancy; Nextcea: Consultancy; Octapharma: Consultancy; MEI Pharma: Consultancy; Eli Lilly and Company: Consultancy; Astra-Zeneca: Consultancy; TG Therapeutics: Consultancy; Sunesis: Consultancy; Loxo: Consultancy, Research Funding; Sun: Research Funding; Rigel Pharmaceuticals: Consultancy; Pfizer: Consultancy; Catapult: Consultancy; Dynamo Therapeutics: Consultancy; Pharmacyclics: Consultancy; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other; Gilead: Consultancy, Research Funding; Genentech: Consultancy; BeiGene: Consultancy; Invectys: Membership on an entity's Board of Directors or advisory committees, Other: DSMC; Janssen: Honoraria; AbbVie: Consultancy; Kite: Consultancy; Juno/Celgene: Consultancy; Verastem: Consultancy, Research Funding; Acerta: Consultancy. Eyre:AbbVie: Consultancy, Honoraria, Other: travel support; KITE, AZ, Loxo Oncology at Lilly: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Other: travel support; Gilead: Consultancy, Honoraria, Other: travel support. Skarbnik:Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CLL Society: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion: Consultancy; Beigene: Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Verastem: Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bannerji:Regeneron Pharmaceuticals: Research Funding; F. Hoffmann-La Roche Ltd/Genentech, Inc and Pharmacyclics LLC, an AbbVie Company: Research Funding; Sanofi-Pasteur: Other: Spouse is employee; AbbVie: Research Funding. Eichhorst:BeiGene: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding; ArQule: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: travel support, Research Funding; Oxford Biomedica: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding. Brander:Verastem: Consultancy, Honoraria, Other, Research Funding; NCCN: Other; Genentech: Consultancy, Honoraria, Other, Research Funding; Juno/Celgene/BMS: Other, Research Funding; MEI Pharma: Other, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Other, Research Funding; Pfizer: Consultancy, Other; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; NCCN: Other; Novartis: Consultancy, Other; Teva: Consultancy, Honoraria; Tolero: Research Funding; Ascentage: Other, Research Funding; ArQule: Consultancy, Other, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Tolero: Research Funding; Teva: Consultancy, Honoraria; Novartis: Consultancy, Other; DTRM: Other, Research Funding; AstraZeneca: Consultancy, Honoraria, Other, Research Funding; BeiGene: Other, Research Funding. Sharmokh:AbbVie: Current Employment, Current equity holder in publicly-traded company. Jiang:AbbVie: Current Employment, Other: may hold stock or options. Pena:AbbVie: Current Employment, Current equity holder in publicly-traded company. Kamalakar:AbbVie: Current Employment, Other: may hold stock or other options. Emechebe:AbbVie: Current Employment, Current equity holder in publicly-traded company. Pivneva:Novartis: Consultancy, Other: Irina Pivneva is an employee of Analysis Group, Inc which received consultancy fees from Novartis.. Burne:Analysis Group, Inc., which has received consultancy fees from AbbVie: Current Employment. Guerin:Abbvie: Consultancy, Other; Novartis Pharmaceuticals Corporation: Consultancy, Other: Annie Guerin is an employee of Analysis Group, Inc. which received consultancy fees from Novartis.; Sanofi Genzyme: Consultancy, Other: Annie Guerin is an employee of Analysis Group, Inc. which received consultancy fees from Sanofi Genzyme.. Davids:Celgene: Consultancy; Research to Practice: Honoraria; AbbVie: Consultancy; Sunesis: Consultancy; Genentech: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Surface Oncology: Research Funding; BeiGene: Consultancy; Novartis: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Bristol Myers Squibb: Research Funding; Janssen: Consultancy; Adaptive Biotechnologies: Consultancy; Ascentage Pharma: Consultancy, Research Funding; Gilead Sciences: Consultancy; Eli Lilly: Consultancy; Syros Pharmaceuticals: Consultancy; Zentalis: Consultancy; Merck: Consultancy; TG Therapeutics: Consultancy, Research Funding; Verastem: Consultancy, Research Funding. Mato:AbbVie: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Loxo: Consultancy, Research Funding; Janssen: Consultancy, Research Funding.

Introduction Recent randomized trials have demonstrated the efficacy of ibrutinib-based therapy in the treatment of patients with CLL. In Alliance A041202, a higher than expected number of unexplained deaths were reported with front-line ibrutinib in a patient population aged at least 65 years compared to ECOG 1912, which included patients up to 70 years of age. Methods Therefore, we conducted a retrospective analysis to investigate whether ibrutinib was associated with a greater mortality in older patients outside of a clinical trial setting. This multicenter analysis was performed by investigators at 20 academic and community practices. Results Amongst the 391 patients included, there was no correlation between age and response rate, PFS, or OS. However, there was a trend to higher rate of deaths in patients >65-years-old (8.7% vs 3.8%, p=0.097), with an increased number of early deaths (13 vs 4, p=0.3). Conclusion These data suggest greater intolerance, and possibly mortality, with ibrutinib in an older population. Patients should be educated regarding the potential complications related to ibrutinib and symptoms of concern to report.

Treon et al provide early clinical data supporting a theoretical rationale for continuing ibrutinib in patients receiving the drug during COVID-19 illness.

BACKGROUND: Treatment of chronic lymphocytic leukemia (CLL) with a fixed-duration venetoclax (Ven)-based regimen is now a standard of care (SOC) option for both frontline and relapsed refractory (R/R) disease based on results of the CLL14 and MURANO trials (Fischer et al NEJM 2019, Seymour et al NEJM 2018). As fixed-duration Ven regimens are now a SOC, it is expected that an increasing number of patients (pts) will ultimately progress after Ven exposure and require additional CLL-directed therapy. While many discuss re-treatment with Ven as a subsequent treatment option, the current literature contains response data on an extremely limited number of evaluable pts (11 pts MURANO, overall response rate (ORR) 55%; 3 pts VEN 365, ORR 100%). Whether re-treatment with Ven is an acceptable option remains an important unanswered clinical question. METHODS: We conducted a multicenter, retrospective study of CLL pts treated with a Ven-based regimen (Ven1) and then re-treated with a second Ven-based regimen (Ven2) in a later line of therapy (LOT). Data were collected from 13 centers and the CLL Collaborative Study of Real-World Evidence database. CLL pts were eligible for inclusion if they were treated with a Ven-based regimen in any LOT and then re-treated with a Ven-based regimen as a later LOT. Collected data included demographics, prognostic disease characteristics, tumor lysis syndrome (TLS) risk and incidence, clinical response and reasons for treatment discontinuation (dc). The primary study endpoint was investigator-assessed ORR (CR: complete response, PR: partial response, SD: stable disease, PD: progression of disease, iwCLL 2018). Kaplan-Meier method was used to estimate progression free survival (PFS). All other analyses were descriptive. RESULTS: We identified 25 pts who were re-treated with Ven. Pt characteristics prior to treatment with Ven1 are summarized in Table 1. In 24% of pts (n=6), Ven1 was administered as part of a clinical trial. Median prior LOT was 2 (range 0-10) with 12.0% treatment naïve and 60% with prior BTKi exposure. The majority of pts had ≥1 high-risk prognostic marker: del17p (39%), TP53 mut (27%), complex karyotype ≥5 abnormalities (30%) and unmutated IGHV (84%). For Ven1, treatment regimens, TLS risk, and dose are summarized in Table 2. With a median duration of exposure of 15 months (mos) (64% pts > 12 mos) for Ven1, the ORR was 88% (CR: 48%, PR: 40%, Figure 1A). Ten pts had minimal residual disease (MRD) assessments by flow cytometry; 8 pts (80%) achieved undetectable MRD (10^-4). Most common reasons for Ven1 dc included: toxicity (28%), completion of planned therapy (24%), MD/pt preference (24%), other (12%), alloHSCT (4%) and cost (4%). There was a median of 8.7 mos (36% > 12 mos) between Ven1 and the initiation of Ven2, and 88% did not receive another LOT between Ven1 and Ven2. Reasons for Ven2 initiation were either CLL progression (87.5%) or MRD-positive relapse (12.5%). For Ven2, TLS risk, TLS incidence and dose information are outlined in Table 2. TLS was a rare event during Ven re-treatment (4.5%, lab only). For Ven2, Ven monotherapy was the most common regimen (52%). Standard Ven dose-escalation was used for re-initiation in 17 of 19 pts with available data, however 1 pt started Ven2 at 400 mg daily (no TLS) and another underwent a prolonged ramp-up period. At the time of this analysis, 18 pts had available response assessments for Ven2: ORR is 72.2% (CR: 4, PR: 9, SD: 4 and PD: 1, Figure 1B). Median time from Ven2 to progression or last follow up is 8 mos (0.2-29 mos). Median PFS has not been reached. Estimated 12-month PFS is 69.1%. For pts with a CR to Ven2, median follow up time is 14.5 mos vs 7 mos for pts with PR or SD. Of 25 pts re-treated with Ven, 68% remain on Ven2 presently and 32% have discontinued Ven2, including due to CLL progression (n=4), completion of planned therapy (n=1), unrelated death (n=1), MD/pt preference (n=1). CONCLUSIONS: To our knowledge, this is the largest reported cohort of CLL pts re-treated with Ven after a prior Ven-based regimen. The high ORR in this pt population (median 2 prior therapies) suggests that re-treatment is a promising strategy and should be considered in treatment sequencing algorithms. Notably, pts with a CR to Ven2 had a longer median follow up than those with a PR or SD, suggesting a likelihood of deeper responses with time. Given the promising ORR, further research to prospectively validate Ven re-treatment is warranted. Updated data will be presented. Disclosures Allan: Celgene, Genentech, Janssen, TG Therapeutics: Research Funding; Abbvie, Janssen, AstraZeneca, Pharmacyclics: Honoraria; Acerta, Genentech, Abbvie, Sunesis, Ascentage, Pharmacyclics, Janssen, AstraZeneca, BeiGene: Consultancy. Sail:AbbVie Inc.: Current Employment, Current equity holder in publicly-traded company. Manzoor:Abbvie: Current Employment, Other: may hold stock or stock options. Pu:Takeda Pharmaceuticals: Consultancy. Barr:Gilead: Consultancy; Janssen: Consultancy; AstraZeneca: Consultancy, Research Funding; Abbvie/Pharmacyclics: Consultancy, Research Funding; Verastem: Consultancy; Morphosys: Consultancy; TG therapeutics: Consultancy, Research Funding; Seattle Genetics: Consultancy; Celgene: Consultancy; Merck: Consultancy; Genentech: Consultancy. Coombs:LOXO Oncology: Honoraria; MEI Pharma: Honoraria; Abbvie: Consultancy, Honoraria; Genentech: Honoraria; AstraZeneca: Honoraria; Octapharma: Honoraria; Novartis: Honoraria. Schuster:AlloGene, AstraZeneca, BeiGene, Genentech, Inc./ F. Hoffmann-La Roche, Juno/Celgene, Loxo Oncology, Nordic Nanovector, Novartis, Tessa Therapeutics: Consultancy, Honoraria; Novartis, Genentech, Inc./ F. Hoffmann-La Roche: Research Funding. Skarbnik:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion: Consultancy; Beigene: Speakers Bureau; Verastem: Speakers Bureau; Novartis: Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CLL Society: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rhodes:Verastem: Consultancy; Abbvie/Genentech: Consultancy; Pharmacyclics: Consultancy; AstraZeneca: Consultancy. Barrientos:Janssen: Honoraria; Sandoz: Consultancy; Oncternal Therapeutics: Research Funding; Bayer: Consultancy; Genentech: Consultancy; Gilead: Consultancy; AstraZeneca: Consultancy. Roeker:American Society of Hematology: Research Funding; Abbott Laboratories: Other: spouse with minority ownership interest ; AbbVie: Other: spouse with minority ownership interest . Leslie:Celgene: Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Honoraria, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Epizyme: Honoraria, Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kamdar:Roche: Research Funding. Choi:Pharmacyclics/Abbvie: Research Funding; Genentech: Consultancy. Simkovic:Abbvie: Consultancy, Other: travel expenses. Lansigan:Seattle Genetics: Consultancy; BMS: Consultancy; BMS Steering Committee for MAGNIFY Program: Membership on an entity's Board of Directors or advisory committees; Spectrum Pharma: Consultancy, Research Funding. Zelenetz:Novartis: Consultancy; Gilead: Research Funding; Janssen: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Genentech/Roche: Consultancy; Roche: Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnology: Consultancy; MorphoSys: Research Funding; Amgen: Consultancy; Sandoz: Research Funding; Celgene: Research Funding; MEI Pharma: Research Funding. Moskowitz:Merck: Research Funding; Seattle Genetics: Research Funding; Bristol-Myers Squibb: Research Funding; Miragen Therapeutics: Consultancy; Incyte: Research Funding; Merck: Consultancy; Imbrium Therapeutics, L.P.: Consultancy; Seattle Genetics: Consultancy. Goy:Morphosys: Research Funding; AbbVie: Research Funding; MD Anderson: Research Funding; Regional Cancer Care Associates/OMI: Current Employment; Infinity Verastem: Research Funding; Infinity: Research Funding; Karyopharm: Research Funding; Genentech/Roche: Research Funding; CALBG: Research Funding; Constellation: Research Funding; Bayer: Research Funding; PracticeUpdate Oncology: Consultancy; RCCA/OMI: Current Employment; Acerta: Consultancy, Honoraria, Other: leadership role, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: leadership role, Research Funding; Celgene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: leadership role, Research Funding; COTA: Consultancy, Current equity holder in publicly-traded company, Other: leadership role; Kite, a Gilead Company: Consultancy, Current equity holder in publicly-traded company, Honoraria, Other: leadership role, Research Funding; Xcenda: Consultancy; Hackensack UMC and University of Nebraska: Research Funding. Feldman:Pfizer: Research Funding; Kyowa Kirin: Consultancy, Research Funding; Eisai: Research Funding; Cell Medica: Research Funding; Amgen: Research Funding; Pharmacyclics: Honoraria, Other, Speakers Bureau; Abbvie: Honoraria; Bayer: Consultancy, Honoraria; Trillium: Research Funding; Portola: Research Funding; Janssen: Speakers Bureau; AstraZeneca: Consultancy; Viracta: Research Funding; Rhizen: Research Funding; Corvus: Research Funding; BMS: Consultancy, Honoraria, Research Funding; Kite: Honoraria, Other: Travel expenses, Speakers Bureau; Celgene: Honoraria, Research Funding; Takeda: Honoraria, Other: Travel expenses; Seattle Genetics, Inc.: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau. Furman:Verastem: Consultancy; Genentech: Consultancy; Beigene: Consultancy; AstraZeneca: Consultancy, Research Funding; Acerta: Consultancy; Abbvie: Consultancy; TG Therapeutics: Consultancy, Research Funding; Sunesis: Consultancy; Pharmacyclics: Consultancy; Oncotarget: Consultancy; Loxo Oncology: Consultancy; Janssen: Consultancy, Speakers Bureau; Incyte: Consultancy. Mato:Genentech: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; BeiGene: Consultancy; LOXO: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Adaptive: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding.

Elderly chronic lymphocytic leukaemia (CLL) patients treated outside of trials have notably greater toxicity with the Bruton’s tyrosine kinase inhibitor ibrutinib compared to younger patients. It is not known whether the same holds true for the B-cell lymphoma 2 inhibitor venetoclax. We provide a comprehensive analysis of key safety measures and efficacy in 342 patients comparing age categories ≥75 and

Purpose: Clinical trials of venetoclax reported negligible rates of clinical tumor lysis syndrome (TLS) in patients with chronic lymphocytic leukemia (CLL) when using an extended dose escalation schedule. We aimed to understand TLS prophylaxis, rates of select adverse events (AE), and impact of dosing modifications in routine clinical practice. Experimental Design: This retrospective cohort study included 297 CLL venetoclax-treated patients outside of clinical trials in academic and community centers. Demographics, baseline disease characteristics, venetoclax dosing, TLS risk and prophylaxis, and AEs were collected. Results: The group was 69% male, 96% had relapsed/refractory CLL, 45% had deletion chromosome 17p, 84% had unmutated IGHV, 80% received venetoclax monotherapy, and median age was 67. TLS risk was categorized as low (40%), intermediate (32%), or high (28%), and 62% had imaging prior to venetoclax initiation. Clinical TLS occurred in 2.7% of patients and laboratory TLS occurred in 5.7%. Pre-venetoclax TLS risk group and creatinine clearance independently predict TLS development in multivariable analysis. Grade 3/4 AEs included neutropenia (39.6%), thrombocytopenia (29.2%), infection (25%), neutropenic fever (7.9%), and diarrhea (6.9%). Twenty-two patients (7.4%) discontinued venetoclax due to an AE. Progression-free survival was similar regardless of number of dose interruptions, length of dose interruption, and stable venetoclax dose. Conclusions: These data provide insights into current use of venetoclax in clinical practice, including TLS rates observed in clinical practice. We identified opportunities for improved adherence to TLS risk stratification and prophylaxis, which may improve safety.

A regimen of escalating doses of thalidomide, in combination with bortezomib and high-dose melphalan (mel/vel/thal), was evaluated as a conditioning regimen for autologous stem cell transplantation (ASCT) in multiple myeloma (MM) patients with a prior transplant who had relapsed or achieved less than a complete remission following a prior ASCT. Thalidomide was dose escalated starting from 600 mg to 1000 mg on days −5 to −1 in a 3 × 3 design, bortezomib was administered at 1.6 mg/m2 intravenously on days −4 and −1 and melphalan 200 mg/m2 was administered on day −2. No dose-limiting toxicity was seen in the phase I portion of the trial. An additional 20 patients were enrolled at the maximum tolerated dose of thalidomide of 1000 mg daily. The overall response rate was 69% with 38% complete remission. Median PFS and OS were 9.3 and 65.4 months, respectively, with a median follow-up of 17.8 months. The most common grade 3–4 adverse events (AEs) were neutropenic fever (58.6%), mucositis (6.9%), and diarrhea (6.9%). Serious AEs included somnolence (13.8%) and tumor lysis syndrome (3.4%). The addition of high-dose thalidomide to bortezomib and melphalan as conditioning for salvage ASCT was well tolerated and was an effective conditioning regimen.

Purpose Trials of tocilizumab in patients with severe COVID-19 pneumonia have demonstrated mixed results, and the role of tocilizumab in combination with other treatments is uncertain. Here we evaluated whether tocilizumab plus remdesivir provides greater benefit than remdesivir alone in patients with severe COVID-19 pneumonia. Methods This randomized, double-blind, placebo-controlled, multicenter trial included patients hospitalized with severe COVID-19 pneumonia requiring > 6 L/min supplemental oxygen. Patients were randomly assigned (2:1 ratio) to receive tocilizumab 8 mg/kg or placebo intravenously plus ≤ 10 days of remdesivir. The primary outcome was time from randomization to hospital discharge or “ready for discharge” (defined as category 1, assessed by the investigator on a 7-category ordinal scale of clinical status) to day 28. Patients were followed for 60 days. Results Among 649 enrolled patients, 434 were randomly assigned to tocilizumab plus remdesivir and 215 to placebo plus remdesivir. 566 patients (88.2%) received corticosteroids during the trial to day 28. Median time from randomization to hospital discharge or “ready for discharge” was 14 (95% CI 12–15) days with tocilizumab plus remdesivir and 14 (95% CI 11–16) days with placebo plus remdesivir [log-rank P = 0.74; Cox proportional hazards ratio 0.97 (95% CI 0.78–1.19)]. Serious adverse events occurred in 128 (29.8%) tocilizumab plus remdesivir and 72 (33.8%) placebo plus remdesivir patients; 78 (18.2%) and 42 (19.7%) patients, respectively, died by day 28. Conclusions Tocilizumab plus remdesivir did not shorten time to hospital discharge or “ready for discharge” to day 28 compared with placebo plus remdesivir in patients with severe COVID-19 pneumonia. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-021-06507-x.

Autologous hematopoietic stem cell transplantation (ASCT) is a standard-of-care treatment for many hematologic malignancies. Progression of disease after ASCT is the primary cause of treatment failure. In this Phase Ib trial, we studied the safety and clinical effect of combined checkpoint inhibition therapy (CPIT) with ipilimumab and nivolumab as a consolidation strategy after ASCT for patients with high-risk diffuse large B cell lymphoma (DLBCL), mature T cell lymphoma (TCL), and multiple myeloma (MM). Starting at 14 to 28 days after ASCT, patients received ipilimumab (1 mg/kg i.v. on day 1 of weeks 1, 4, 7, 10, 16, and 22) and nivolumab (3 mg/kg i.v. on day 1 of weeks 1, 4, 7, 10, 12, 14, 16, 18, 20, 22, 24, and 26). Patients received a median of 5 doses of ipilimumab and 8 doses of nivolumab. Thirty-five patients were included in the intent-to-treat population. Ninety-four percent of the patients experienced immune-related adverse events (irAEs) of any grade. Ninety-seven percent of irAEs resolved spontaneously or after holding study drugs and instituting high-dose corticosteroid therapy. Progression-free and overall survival at 18 months post-ASCT for each disease cohort were 85.7% and 100% for primary refractory DLBCL, 28.6% and 57.1% for relapsed DLBCL, not evaluable and 80% for frontline TCL, 25% and 75% for relapsed TCL, 57.1% and 87% for high-risk transplant-naive MM, and 40% and 100% for MM relapsed within 3 years of first ASCT. We conclude that combined CPIT appears to be tolerable as a consolidation strategy after ASCT and in addition to the potential clinical efficacy observed in some subsets of disease, T cell receptor repertoire, T regulatory cell phenotype, and gut microbiota profiles provide a biologic rationale warranting further study of this approach.

Venetoclax is a BCL2 inhibitor approved for 17p-deleted relapsed/refractory chronic lymphocytic leukemia with activity following kinase inhibitors. We conducted a multicenter retrospective cohort analysis of patients with chronic lymphocytic leukemia treated with venetoclax to describe outcomes, toxicities, and treatment selection following venetoclax discontinuation. A total of 141 chronic lymphocytic leukemia patients were included (98% relapsed/refractory). Median age at venetoclax initiation was 67 years (range 37-91), median prior therapies was 3 (0-11), 81% unmutated IGHV, 45% del(17p), and 26.8% complex karyotype (≥ 3 abnormalities). Prior to venetoclax initiation, 89% received a B-cell receptor antagonist. For tumor lysis syndrome prophylaxis, 93% received allopurinol, 92% normal saline, and 45% rasburicase. Dose escalation to the maximum recommended dose of 400 mg daily was achieved in 85% of patients. Adverse events of interest included neutropenia in 47.4%, thrombocytopenia in 36%, tumor lysis syndrome in 13.4%, neutropenic fever in 11.6%, and diarrhea in 7.3%. The overall response rate to venetoclax was 72% (19.4% complete remission). With a median follow up of 7 months, median progression free survival and overall survival for the entire cohort have not been reached. To date, 41 venetoclax treated patients have discontinued therapy and 24 have received a subsequent therapy, most commonly ibrutinib. In the largest clinical experience of venetoclax-treated chronic lymphocytic leukemia patients, the majority successfully completed and maintained a maximum recommended dose. Response rates and duration of response appear comparable to clinical trial data. Venetoclax was active in patients with mutations known to confer ibrutinib resistance. Optimal sequencing of newer chronic lymphocytic leukemia therapies requires further study.

Attempts to improve upon the activity of ibrutinib in chronic lymphocytic leukemia (CLL) include the addition of targeted therapies. The combination of lenalidomide and rituximab demonstrated an overall response rate (ORR) of 66% with a complete response (CR) of 12% in the relapsed/refractory setting. Based on these data, we conducted a phase 1 study of rituximab (R), lenalidomide (L), and ibrutinib (I) in relapsed/refractory CLL. Patients received R 375 mg/m2 cycles 1 to 6 day 1, L on cycles 1 to 12 days 1 to 21, and I until disease progression. Dose escalation used a standard 3+3 design from a dose level (DL) of L 5 mg (DL1) and increasing to 15 mg (DL3) for a total of 3 dose levels. Twelve patients were enrolled; there were 2 dose-limiting toxicities of grade 4 neutropenia at DL3; thus, DL2 was the recommended phase 2 dose. A high incidence of sustained grade 4 neutropenia occurred at all dose levels, prompting study withdrawal in 5 patients, despite growth factor support. The ORR was 67%; ORR at the RP2D was 100% (1 CR). The 12-month progression-free survival at the RP2D was 83%. Preliminary efficacy data with the triplet did not appear superior to prior reports of the rituximab-lenalidomide doublet or single-agent ibrutinib. Given these findings and the sustained neutropenia, this regimen was not pursued. The study was registered at www.clinicaltrials.gov as #NCT02200848.

Context: Results from ELEVATE-TN (NCT02475681) at a median follow-up of 28.3 months demonstrated superior efficacy of acalabrutinib (A) ± obinutuzumab (O) compared with O + chlorambucil (Clb) in TN CLL (Sharman et al. Lancet 2020;395:1278-91). Objective: To report the results from a 4-year update of ELEVATE-TN. Design: Randomized, multicenter, open-label, 3-arm, Phase 3 study. Patients: TN CLL. Interventions: Patients received A±O or O+Clb. Crossover to A monotherapy was permitted in patients who progressed on O+Clb. Main Outcome Measures: Investigator-assessed (INV) progression-free survival PFS, INV ORR, OS, and safety were evaluated. Results: 535 patients (A+O, n=179; A, n=179; O+Clb, n=177) were randomized with a median age of 70 y; 14% had del(17p) and/or mutated TP53. At a median follow-up of 46.9 months (range, 0.0–59.4; data cutoff: Sept 11, 2020), median PFS was not reached (NR) for A+O and A patients vs 27.8 months for O+Clb patients (both P Conclusions: With a median follow-up of 46.9 months (~4y), the efficacy and safety of A+O and A monotherapy was maintained, with an increase in CR since the interim analysis (from 21% to 27% [A+O] and from 7% to 11% [A]) and low rates of discontinuation.

Updated analysis confirms sustained poor prognosis of COVID-19 in patients with lymphoma in Latin America: A cohort of 160 patients from GELL. Introduction: Ongoing SARS-COV-2 pandemic has impacted the management of cancer patients worldwide. Several reports have demonstrated inferior outcomes of patients with hematological malignancies, including higher rates of intensive care unit admission, need for mechanical ventilation and death. The impact of COVID-19 is profound in resource-restricted countries, including Latin America. Most cohorts reported have not included patients from Latin America, and there is paucity of data of the outcome of cancer patients with COVID-19 in low- and middle-income countries. Grupo de Estudio De Linfoproliferativos En Latino-America (GELL )is a collaborative network of hematological centers in 13 countries in Latin America. We report updated outcomes of lymphoma patients diagnosed with COVID-19 in Latin America. Methods: We conducted a retrospective study including patients with a diagnosis of lymphoma and COVID-19 infection. Patients with chronic lymphocytic leukemia/small lymphocytic lymphoma were excluded from the analysis We defined active disease as follow: (1) patients with detectable disease either prior to initiating therapy or upon relapse, and/or (2) patients undergoing active cancer treatment. The primary outcome was overall survival at 100 days. Survival curves were estimated using the Kaplan Meier method. Uni and multivariable analysis were carried out with Cox model. Results: A total of 160 patients were available for analysis. Median age was 60 years old. Hypertension was the most common comorbidity (33%). Most patients had aggressive lymphomas (62%), including 43% of patients with diffuse large B-Cell lymphoma (DLBCL). Follicular lymphomas were observed in 13% of patients and Hodgkin lymphoma in 12.5% of patients. With a median follow-up of 37 days, the 100-day OS was 64% (95CI 56-74%, fig. 1). In univariate analysis, age (HR 1.03, p=0.0025), hypertension (HR 2.01, p=0.017), >1 number of prior lines (HR 2.78, p=0.011), patients currently on treatment (HR 1.83, p=0.043), ferritin >2000 ng/mL (HR 4.74 p=0.00047) were associated with inferior OS. In multivariate analysis, age (HR 1.03, p=0.0026) and patients currently on treatment (HR 1.82, p=0.04) had inferior OS. There was a trend towards inferior outcomes in patients receiving monoclonal antibodies in univariate analysis (HR 1.82, p=0.081) but not in multivariable analysis (HR=1.29, p=0.48). Use of steroids was not statistically related to mortality (HR 1.79, p=0.074). Finally, contrary to other cohorts, no improvement in OS was observed in patients diagnosed later on the pandemic (fig. 2). Conclusion: In this large cohort of Latin American patients with lymphoma malignancies, our updated analysis showed a maintained dismal prognosis with COVID-19 infection. With a median follow up of 37 days, the 100-day OS was 64%. Older age and ongoing active cancer treatment were significantly associated with mortality. The use of monoclonal antibodies and systemic corticosteroids were not statistically associated to poor survival. Current efforts are focused on improving immunization in the Latin American population. There is an unmet need for improving survival in patients with hematologic malignancies and COVID-19 infection. Figure 1 Figure 1. Disclosures Perini: Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Astra Zeneca: Honoraria, Speakers Bureau; MSD: Honoraria, Speakers Bureau. Otero: ASTRA ZENECA: Current Employment. Abello: Dr Reddy's: Research Funding; Amgen: Honoraria; Janssen: Honoraria. Castillo: Abbvie: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy; Roche: Consultancy; TG Therapeutics: Research Funding.

Introduction: The management of CLL patients historically utilized FD chemoimmunotherapy (CIT), including fludarabine, cyclophosphamide and rituximab (FCR), or bendamustine and rituximab (BR). That changed with the introduction of Bruton Tyrosine Kinase inhibitors (BTKi) as an option for oral targeted monotherapy delivered continuously until disease progression or intolerance. Recently, novel combinations that include a B-cell lymphoma 2 inhibitor (BCL2i), such as venetoclax, have been developed as FD therapy. In addition, though not FDA approved, MRD assessment is emerging as a potential tool to guide FD therapy. Understanding the patient and their caregiver perspectives on FD and MRD is critical to providing the best care. Methods: CLL Society developed a web-based survey instrument of multiple-choice questions to assess patient and caregiver awareness, understanding, and preferences with MRD and FD therapies, where FD referred to both time and MRD guided limited duration therapies. Patients and caregivers were invited to participate via message boards, CLL Society's website, email, and online communities. Results: A total of 607 (96%) self-identified US patients and 36 (5%) caregivers, who answered on behalf of patients in their care, completed the survey between 31/AUG/2020 and 31/JAN/2021. The mean patient age was 64 (range, 30-90) years, 54% were female, 169 patients (27%) treatment-naïve, 239 (38%) with one line of prior therapy, and 214 (34%) with two or more. Targeted agents (e.g., venetoclax, ibrutinib, acalabrutinib, idelalisib, and duvelisib) had been used by 401 (64%). FD use with some novel therapies was known of by 565 (90%) patients, while 588 (93%) knew some were used as continuous daily treatment until disease progression or intolerance. If effectiveness and side effects were assumed similar, 485 (77%) preferred FD, and 398 (63%) wanted that finite treatment to be guided by MRD status. Only 42 (7%) preferred continuous therapy until disease progression or intolerance. The chance for continued remission while off treatment was ranked as a very important potential benefit after stopping a FD therapy by 581 (92%) patients. When considering therapy, 589 (93%), 575 (91%), 447 (71%), 415 (66%), 302 (48%), and 288 (46%) rated having overall survival, having future therapeutic options, avoiding chemotherapy, the ability to reach undetectable (u)MRD, minimal lab and office visits, and FD therapy as very important, respectively (Fig. 1). Being tested for MRD at least once was reported by 215 (34%), while 327 (52%) had not been tested, and 88 (14%) were unsure. There were 562 (89%) who were somewhat or very familiar with the term MRD, while 450 (71%) were confident of understanding what MRD testing measures, and 446 (70%) understood its role in CLL. Only 225 (36%) stated they understood different testing methods. While self-rated understanding of the indications for MRD testing was relatively high, some wanted testing done when not clinically indicated, such as when there was persistent CLL by routine laboratory findings, or at the time of diagnosis (Fig. 2). Respondents were mixed in their stated understanding as to which therapies could result in uMRD, with 241 (38%), 197 (32%), and 195 (32%) not knowing if CIT, BCL2i, and BTKi, could lead to uMRD, respectively. Two hundred and sixty-five (42%), 84 (13%), and 57 (9%) believed it was possible for most on a BCL2i, BTKi, or CIT to achieve uMRD, respectively (Fig. 3). If patients had evidence of MRD at the end of treatment, 365 (58%) would request frequent monitoring but would make no immediate treatment decisions based on MRD status, 279 (44%) were unsure, and only 88 (14%) would want further treatment immediately. Conclusions: The results from this patient-based study reveal a high awareness of FD therapies and MRD testing, as well as a clear preference for FD among internet-active patients and caregivers. However, there are gaps in the knowledge base, thus significant educational opportunities. Limitations included the opt-in sample where the survey results may not be projectable to the total CLL population. Moreover, the survey was not designed to assess preferences if either FD or continuous therapy offered improved outcomes. Nonetheless, as the potential role of MRD and FD therapy grows in CLL it will be incumbent on clinicians to ensure patients are well informed and engaged to help them better share therapeutic decisions. Figure 1 Figure 1. Disclosures Koffman: AbbVie: Current equity holder in publicly-traded company; AstraZeneca: Current equity holder in publicly-traded company, Honoraria; Beigene: Current equity holder in publicly-traded company; Bristol Myer Squibb: Current equity holder in publicly-traded company, Honoraria; Gilead: Current equity holder in publicly-traded company; Johnson & Johnson: Current equity holder in publicly-traded company, Honoraria; Sunesis Pharmaceuticals: Current equity holder in publicly-traded company; TG Therapeutics: Current equity holder in publicly-traded company; Regeneron: Current equity holder in publicly-traded company; Miragen Therapeutics: Current equity holder in publicly-traded company; Novartis: Membership on an entity's Board of Directors or advisory committees; Portola Pharma: Current equity holder in publicly-traded company; MEI Pharma: Current equity holder in publicly-traded company; Merck: Current equity holder in publicly-traded company. Stewart: Johnson & Johnson: Current equity holder in publicly-traded company; Novartis: Current equity holder in publicly-traded company; Dr. Reddy's Laboratories Limited: Current equity holder in publicly-traded company; Adaptive Biotechnologies: Current equity holder in publicly-traded company; Pacific Biosciences: Current equity holder in publicly-traded company. Byrd: Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Newave: Membership on an entity's Board of Directors or advisory committees. Danilov: Bayer Oncology: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Takeda Oncology: Research Funding; Rigel Pharm: Honoraria; TG Therapeutics: Consultancy, Research Funding; Abbvie: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Gilead Sciences: Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; SecuraBio: Research Funding; Astra Zeneca: Consultancy, Honoraria, Research Funding. Davids: BeiGene: Consultancy; Janssen: Consultancy; Ascentage Pharma: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Astra-Zeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; AbbVie: Consultancy; Surface Oncology: Research Funding; TG Therapeutics: Consultancy, Research Funding; Celgene: Consultancy; Verastem: Consultancy, Research Funding; Eli Lilly and Company: Consultancy; MEI Pharma: Consultancy; Merck: Consultancy; Research to Practice: Consultancy; Takeda: Consultancy. Furman: Beigene: Consultancy; Acerta/AstraZeneca: Consultancy; Janssen: Consultancy, Honoraria; Sunesis: Consultancy; Genentech: Consultancy; Incyte: Consultancy; Pharmacyclics: Consultancy; TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Sanofi: Consultancy; Morphosys: Consultancy; Verastem: Consultancy; X4 Pharmaceuticals: Consultancy; Oncotracker: Consultancy; Abbvie: Consultancy, Honoraria, Other: Expert testimony; AstraZeneca: Honoraria. Jain: Bristol Myers Squibb: Honoraria, Research Funding; Genentech: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Fate Therapeutics: Research Funding; Beigene: Honoraria; AbbVie: Honoraria, Research Funding; Pfizer: Research Funding; TG Therapeutics: Honoraria; Cellectis: Honoraria, Research Funding; Precision Biosciences: Honoraria, Research Funding; ADC Therapeutics: Honoraria, Research Funding; Aprea Therapeutics: Research Funding; Adaptive Biotechnologies: Honoraria, Research Funding; Servier: Honoraria, Research Funding; Janssen: Honoraria; Incyte: Research Funding; Pharmacyclics: Research Funding. Kay: Oncotracker: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; Targeted Oncology: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; MEI Pharma: Research Funding; Behring: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Research Funding; CytomX Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Research Funding; Sunesis: Research Funding; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lamanna: Juno Therapeutics, Inc.: Research Funding; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; MingSight Pharmaceuticals, Inc.: Research Funding; Genentech, Inc.: Consultancy, Research Funding; Gilead Sciences, Inc.: Consultancy; TG Therapeutics, Inc: Research Funding; Verastem Oncology: Research Funding; Celgene Corporation: Consultancy; Oncternal Therapeutics: Research Funding; Pharmacyclics: Consultancy; Janssen Pharmaceuticals, Inc.: Consultancy. Mato: MSKCC: Current Employment; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Nurix: Research Funding; BeiGene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; Genmab: Research Funding; AstraZeneca: Consultancy; Sunesis: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Ujjani: Adaptive Biotechnologies: Research Funding; Atara Bio: Consultancy; Janssen: Consultancy; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Honoraria; Gilead: Honoraria; ACDT: Honoraria; Kite, a Gilead Company: Honoraria; Loxo: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Pagel: Kite, a Gilead Company: Consultancy; Incyte/MorphoSys: Consultancy; AstraZeneca: Consultancy; Actinium Pharmaceuticals: Consultancy; Gilead: Consultancy; Pharmacyclics/AbbVie: Consultancy; MEI Pharma: Consultancy; Epizyme: Consultancy; BeiGene: Consultancy.

Background: Targeted therapies including ibrutinib, acalabrutinib and venetoclax (ven) have fundamentally changed the treatment of patients (pts) with chronic lymphocytic leukemia (CLL) leading to improved outcomes and durable remissions for many pts. However, CLL remains an incurable disease and a subset of pts will ultimately have progressive CLL following treatment with a covalent Bruton's Tyrosine Kinase inhibitor (cBTKi, e.g., ibrutinib, acalabrutinib) and ven. Data on efficacy of therapies for "double exposed" pts (i.e., pts exposed to both a cBTKi and ven) are extremely limited. Available approved options include chemoimmunotherapy (CIT) and phosphatidylinositol 3-kinase inhibitors (PI3Ki). However, the landmark clinical trials leading to the approvals of CIT and PI3Kis did not include pts treated with either cBTKi or ven (Furman et al. NEJM 2014, Flinn et al. Blood 2018). Non-covalent BTKis (ncBTKi) and chimeric antigen receptor (CAR) T-cell therapy have demonstrated promising clinical activity in double exposed CLL pts in clinical trials (Mato et al. Lancet 2021, Siddiqi et al. ASH 2020), but have not yet been compared to other novel agents or CIT in clinical trials or real-world analyses. We sought to describe outcomes of therapies for "double exposed" CLL pts. Methods: A retrospective, international, multicenter study was conducted. CLL pts were included if they received a cBTKi and ven and then a subsequent CLL-directed therapy. Therapies for Richter Transformation were excluded. Investigators identified pts at each site and collected data on demographics, disease characteristics, prior therapies, subsequent therapies and response assessments. Information was collected on up to three subsequent lines of therapy (LOT 1-3) per patient. The primary study endpoint was investigator-assessed overall response rate (ORR) per iwCLL 2018 criteria to therapies (LOT 1-3) following both cBTKi and ven. Kaplan-Meier method was used to estimate progression free survival (PFS). All other analyses were descriptive. Analyses were performed using STATA 17.0. Results: We report outcomes on 125 CLL pts who had prior cBTKi and ven and received a subsequent LOT. Baseline characteristics are presented in Table 1. ORR to prior cBTKi was 84.7% and 69.6% to prior ven. The most common reason for discontinuation of prior cBTKi and ven was CLL progression (71.1% cBTKi, 68.8% ven) followed by toxicity (25.6% cBTKi, 16.8% ven). Most common treatment strategies included ncBTKi (n=45), cBTKi (n=43), CIT (n=23), PI3Ki (n=24), alloSCT (n=17), CAR T-cell therapy (n=9), ven re-treatment (n=6), and other (n=44). ORR for selected agents following cBTKi and ven are presented in Table 2. ORR and PFS estimates were as follows: CAR T-cell therapy (85.7%, median PFS 4 months), alloSCT (76.5%, median PFS 11 months), ncBTKi (75.0%, median PFS not reached), PI3Ki (40.9%, median PFS 5 months), CIT (31.8%, median PFS 3 months) and ven re-treatment (ORR 40%, median PFS 14 months). ORR to cBTKi was 53.7%; however, median PFS for pts who discontinued a previous cBTKi for PD was 1 month versus 7 months for pts who discontinued due to AE. Figure 1 shows Kaplan-Meier estimated PFS for ncBTKi, PI3Ki, alloSCT, and CIT. Conclusions: In the largest series of "double exposed" CLL pts, several key findings warrant further investigation and discussion. Practice patterns are variable and no standard of care exists for CLL pts previously treated with a cBTKi and ven. Additionally, approved standard therapies including CIT combinations and PI3Kis yield poor outcomes with responses which are not durable. The low response rates and short PFS for PI3Ki and CIT call into question the use of these therapies as standard comparator arms in planned randomized trials. At this time, ncBTKi has a high ORR with durable responses (median PFS not reached). There appears to be a promising role for alloSCT in select, fit patients (ORR 76.5%, median PFS 11 months), and CAR T-cell therapy should be further explored in this population (ORR 85.7%, median PFS 4 months). Overall, this study highlights a continued unmet need for therapies for "double exposed" CLL pts. Figure 1 Figure 1. Disclosures Thompson: MJH Life Sciences: Honoraria; VJHemOnc: Honoraria; Curio Science: Honoraria. Roeker: Abbot Laboratories: Current equity holder in publicly-traded company; Pharmacyclics: Consultancy; Loxo Oncology: Consultancy; TG Therapeutics: Consultancy; AbbVie, AstraZeneca, Janssen, LOXO, Pharmacyclics, TG Therapeutics, Vaniam Group, Verastem: Consultancy; Pfizer: Consultancy, Research Funding. Coombs: LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Genentech: Honoraria; MEI Pharma: Honoraria. Kamdar: AbbVie: Consultancy; TG Therapeutics: Research Funding; SeaGen: Speakers Bureau; ADC Therapeutics: Consultancy; Adaptive Biotechnologies: Consultancy; AstraZeneca: Consultancy; Celgene: Other; Celgene (BMS): Consultancy; Kite: Consultancy; KaryoPharm: Consultancy; Genentech: Research Funding; Genetech: Other. Pagel: Epizyme: Consultancy; Incyte/MorphoSys: Consultancy; BeiGene: Consultancy; Pharmacyclics/AbbVie: Consultancy; Actinium Pharmaceuticals: Consultancy; AstraZeneca: Consultancy; Gilead: Consultancy; Kite, a Gilead Company: Consultancy; MEI Pharma: Consultancy. Jacobs: MEI Pharma: Research Funding; Adaptive Biotechnologies: Consultancy; Genentech: Consultancy; TG Therapeutics: Research Funding, Speakers Bureau; Verastem: Consultancy; AstraZeneca: Consultancy, Speakers Bureau; ADC Therapeutics: Consultancy; TeneoBio: Research Funding; AbbVie: Consultancy, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding, Speakers Bureau; Jannsen: Speakers Bureau; SecuraBio: Consultancy, Speakers Bureau. Hill: Gentenech: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding. Brander: AbbVie: Consultancy, Other: informCLL registry steering committee, Research Funding; AstraZeneca: Research Funding; BeiGene: Research Funding; ArQule: Research Funding; DTRM: Research Funding; LOXO: Research Funding; Verastem: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Juno Therapeutics/Celgene/Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Ascentage: Research Funding; MEI Pharma: Research Funding; Genentech: Consultancy, Research Funding; NCCN: Other: panel member; Pfizer: Consultancy, Other: Biosimilars outcomes research panel; ArQule/Merck: Consultancy. Shadman: Mustang Bio, Celgene, Bristol Myers Squibb, Pharmacyclics, Gilead, Genentech, Abbvie, TG Therapeutics, Beigene, AstraZeneca, Sunesis, Atara Biotherapeutics, GenMab: Research Funding; Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, Adaptimmune , Mustang Bio and Atara Biotherapeutics: Consultancy. Ujjani: AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Loxo: Research Funding; Adaptive Biotechnologies: Research Funding; Atara Bio: Consultancy; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; TG Therapeutics: Honoraria; Gilead: Honoraria; ACDT: Honoraria; Kite, a Gilead Company: Honoraria. Battiato: Abbvie: Honoraria; Janssen: Honoraria. Rhodes: AbbVie, Genentech, Pharmacyclics, TG Therapeutics: Other: Consultant; Conquer Cancer Foundation Young Investigator Award: Other: Grant/Research Support. Fakhri: Loxo/Lilly: Research Funding. Barr: Morphosys: Consultancy; Gilead: Consultancy; Seattle Genetics: Consultancy; TG Therapeutics: Consultancy; Janssen: Consultancy; AstraZeneca: Consultancy; Beigene: Consultancy; Bristol Meyers Squibb: Consultancy; Abbvie/Pharmacyclics: Consultancy; Genentech: Consultancy. Portell: TG Therapeutics: Honoraria, Research Funding; SeaGen: Research Funding; Kite: Honoraria, Research Funding; Xencor: Research Funding; Abbvie: Research Funding; Pharmacyclics: Honoraria; Merck: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding; Acerta/AstraZeneca: Research Funding; Aptitude Health: Honoraria; Targeted Oncology: Honoraria; Morphosys: Honoraria; Genentech: Research Funding; VelosBio: Research Funding. Lamanna: AbbVie: Consultancy, Research Funding; Verastem Oncology: Research Funding; BeiGene: Consultancy; Pharmacyclics: Consultancy; Celgene Corporation: Consultancy; Oncternal Therapeutics: Research Funding; Janssen Pharmaceuticals, Inc.: Consultancy; Gilead Sciences, Inc.: Consultancy; MingSight Pharmaceuticals, Inc.: Research Funding; Genentech, Inc.: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; TG Therapeutics, Inc: Research Funding; Juno Therapeutics, Inc.: Research Funding. Zelenetz: MorphoSys: Honoraria; Verastem: Honoraria; LFR: Other; Gilead: Honoraria, Research Funding; NCCN: Other; AstraZeneca: Honoraria; MEI Pharma: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Janssen: Honoraria; Gilead: Honoraria; Pharmacyclics: Honoraria; BMS/Celgene/JUNO: Honoraria, Other; Novartis: Honoraria; SecuraBio: Honoraria; Genentech/Roche: Honoraria, Research Funding; MethylGene: Research Funding; Amgen: Honoraria; Beigene: Honoraria, Other, Research Funding. Schuster: Abbvie: Consultancy, Research Funding; Acerta Pharma: Consultancy; AstraZeneca: Consultancy; Adaptive Biotechnologies: Research Funding; BeiGene: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; DTRM: Research Funding; Genetech: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Incyte: Research Funding; Juno Theraputics: Consultancy, Research Funding; Loxo Oncology: Consultancy; Merck: Research Funding; Nordic Nanovector: Consultancy; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; Pharmaclcyclics: Research Funding; Tessa Theraputics: Consultancy; TG Theraputics: Research Funding. Eyre: Secura Bio: Consultancy, Honoraria; Loxo Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Research Funding; Incyte: Consultancy; Beigene: Honoraria, Research Funding; Roche: Consultancy, Honoraria; Gilead/KITE: Honoraria, Other: Travel support for conferences, Research Funding, Speakers Bureau; Janssen: Honoraria; Abbvie: Consultancy, Honoraria, Other: Travel to conferences. Mato: MSKCC: Current Employment; AstraZeneca: Consultancy; Genmab: Research Funding; LOXO: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Nurix: Research Funding.

Ibrutinib, idelalisib, and venetoclax are approved for treating CLL patients in the United States. However, there is no guidance as to their optimal sequence.We conducted a multicenter, retrospective analysis of CLL patients treated with kinase inhibitors (KIs) or venetoclax. We examined demographics, discontinuation reasons, overall response rates (ORR), survival, and post-KI salvage strategies. Primary endpoint was progression-free survival (PFS).A total of 683 patients were identified. Baseline characteristics were similar in the ibrutinib and idelalisib groups. ORR to ibrutinib and idelalisib as first KI was 69% and 81%, respectively. With a median follow-up of 17 months (range 1-60), median PFS and OS for the entire cohort were 35 months and not reached. Patients treated with ibrutinib (versus idelalisib) as first KI had a significantly better PFS in all settings; front-line [hazard ratios (HR) 2.8, CI 1.3-6.3, P = 0.01], relapsed-refractory (HR 2.8, CI 1.9-4.1, P0.001), del17p (HR 2.0, CI 1.2-3.4, P = 0.008), and complex karyotype (HR 2.5, CI 1.2-5.2, P = 0.02). At the time of initial KI failure, use of an alternate KI or venetoclax had a superior PFS when compared with chemoimmunotherapy. Furthermore, patients who discontinued ibrutinib due to progression or toxicity had marginally improved outcomes if they received venetoclax (ORR 79%) versus idelalisib (ORR 46%) (PFS HR .6, CI.3-1.0, P = 0.06).In the largest real-world experience of novel agents in CLL, ibrutinib appears superior to idelalisib as first KI. Furthermore, in the setting of KI failure, alternate KI or venetoclax therapy appear superior to chemoimmunotherapy combinations. The use of venetoclax upon ibrutinib failure might be superior to idelalisib. These data support the need for trials testing sequencing strategies to optimize treatment algorithms.

Although novel agents (NAs) have improved outcomes for patients with chronic lymphocytic leukemia (CLL), a subset will progress through all available NAs. Understanding outcomes for potentially curative modalities including allogeneic hematopoietic stem cell transplantation (alloHCT) following NA therapy is critical while devising treatment sequences aimed at long-term disease control. In this multicenter, retrospective cohort study, we examined 65 patients with CLL who underwent alloHCT following exposure to ≥1 NA, including baseline disease and transplant characteristics, treatment preceding alloHCT, transplant outcomes, treatment following alloHCT, and survival outcomes. Univariable and multivariable analyses evaluated associations between pre-alloHCT factors and progression-free survival (PFS). Twenty-four-month PFS, overall survival (OS), nonrelapse mortality, and relapse incidence were 63%, 81%, 13%, and 27% among patients transplanted for CLL. Day +100 cumulative incidence of grade III-IV acute graft-vs-host disease (GVHD) was 24%; moderate-severe GVHD developed in 27%. Poor-risk disease characteristics, prior NA exposure, complete vs partial remission, and transplant characteristics were not independently associated with PFS. Hematopoietic cell transplantation–specific comorbidity index independently predicts PFS. PFS and OS were not impacted by having received NAs vs both NAs and chemoimmunotherapy, 1 vs ≥2 NAs, or ibrutinib vs venetoclax as the line of therapy immediately pre-alloHCT. AlloHCT remains a viable long-term disease control strategy that overcomes adverse CLL characteristics. Prior NAs do not appear to impact the safety of alloHCT, and survival outcomes are similar regardless of number of NAs received, prior chemoimmunotherapy exposure, or NA immediately preceding alloHCT. Decisions about proceeding to alloHCT should consider comorbidities and anticipated response to remaining therapeutic options.

Limited information is available on the efficacy of front‐line bendamustine and rituximab (BR) in chronic lymphocytic leukemia (CLL) with reduced renal function or coexisting conditions. We therefore analyzed a cohort of real‐world patients and performed a matched adjusted indirect comparison with a cohort of patients treated with ibrutinib. One hundred and fifty‐seven patients with creatinine clearance (CrCl) 6 were treated with BR. The median age was 72 years; 69% of patients had ≥2 comorbidities and the median CrCl was 59.8 mL/min. 17.6% of patients carried TP53 disruption. The median progression‐free survival (PFS) was 45 months; TP53 disruption was associated with a shorter PFS (P = 0.05). The overall survival (OS) at 12, 24, and 36 months was 96.2%, 90.1%, and 79.5%, respectively. TP53 disruption was associated with an increased risk of death (P = 0.01). Data on 162 patients ≥65 years treated with ibrutinib were analyzed and compared with 165 patients ≥65 years treated with BR. Factors predicting for a longer PFS at multivariable analysis in the total patient population treated with BR and ibrutinib were age (HR 1.06, 95% CI 1.02‐1.10, P, Bendamustine and Rituximab was a relatively effective first‐line regimen in real‐world untreated CLL patients with reduced renal function or coexisting conditions without TP53 disruption.In a matched‐adjusted indirect comparison with a cohort of CLL patients treated upfront, ibrutinib provided longer PFS than bendamustine and rituximab in those with advanced stage.

Background: Acalabrutinib is a selective, covalent Bruton tyrosine-kinase inhibitor with activity in chronic lymphocytic leukaemia. We compare the efficacy of acalabrutinib with or without obinutuzumab against chlorambucil with obinutuzumab in patients with treatment-naive chronic lymphocytic leukaemia. Methods: ELEVATE TN is a global, phase 3, multicentre, open-label study in patients with treatment-naive chronic lymphocytic leukaemia done at 142 academic and community hospitals in 18 countries. Eligible patients had untreated chronic lymphocytic leukaemia and were aged 65 years or older, or older than 18 years and younger than 65 years with creatinine clearance of 30–69 mL/min (calculated by use of the Cockcroft-Gault equation) or Cumulative Illness Rating Scale for Geriatrics score greater than 6. Additional criteria included an Eastern Cooperative Oncology Group performance status score of 2 or less and adequate haematologic, hepatic, and renal function. Patients with significant cardiovascular disease were excluded, and concomitant treatment with warfarin or equivalent vitamin K antagonists was prohibited. Patients were randomly assigned (1:1:1) centrally via an interactive voice or web response system to receive acalabrutinib and obinutuzumab, acalabrutinib monotherapy, or obinutuzumab and oral chlorambucil. Treatments were administered in 28-day cycles. To reduce infusion-related reactions, acalabrutinib was administered for one cycle before obinutuzumab administration. Oral acalabrutinib was administered (100 mg) twice a day until progressive disease or unacceptable toxic effects occurred. In the acalabrutinib-obinutuzumab group, intravenous obinutuzumab was given on days 1 (100 mg), 2 (900 mg), 8 (1000 mg), and 15 (1000 mg) of cycle 2 and on day 1 (1000 mg) of cycles 3–7. In the obinutuzumab-chlorambucil group, intravenous obinutuzumab was given on days 1 (100 mg), 2 (900 mg), 8 (1000 mg), and 15 (1000 mg) of cycle 1 and on day 1 (1000 mg) of cycles 2–6. Oral chlorambucil was given (0·5 mg/kg) on days 1 and 15 of each cycle, for six cycles. The primary endpoint was progression-free survival between the two combination-therapy groups, assessed by independent review committee. Crossover to acalabrutinib was allowed in patients who progressed on obinutuzumab-chlorambucil. Safety was assessed in all patients who received at least one dose of treatment. Enrolment for this trial is complete, and the study is registered at ClinicalTrials.gov, NCT02475681. Findings: Between Sept 14, 2015, and Feb 8, 2017, we recruited 675 patients for assessment. 140 patients did not meet eligibility criteria, and 535 patients were randomly assigned to treatment. 179 patients were assigned to receive acalabrutinib-obinutuzumab, 179 patients were assigned to receive acalabrutinib monotherapy, and 177 patients were assigned to receive obinutuzumab-chlorambucil. At median follow-up of 28·3 months (IQR 25·6–33·1), median progression-free survival was longer with acalabrutinib-obinutuzumab and acalabrutinib monotherapy, compared with obinutuzumab-chlorambucil (median not reached with acalabrutinib and obinutuzumab vs 22·6 months with obinutuzumab, hazard ratio [HR] 0·1; 95% CI 0·06–0·17, p

Purpose: Venetoclax-based therapy is a standard-of-care option in first-line and relapsed/refractory chronic lymphocytic leukemia (CLL). Patient management following venetoclax discontinuation remains nonstandard and poorly understood. Experimental Design: To address this, we conducted a large international study to identify a cohort of 326 patients who discontinued venetoclax and have been subsequently treated. Coprimary endpoints were overall response rate (ORR) and progression-free survival for the post-venetoclax treatments stratified by treatment type [Bruton's tyrosine kinase inhibitor (BTKi), PI3K inhibitor (PI3Ki), and cellular therapies]. Results: We identified patients with CLL who discontinued venetoclax in the first-line (4%) and relapsed/refractory settings (96%). Patients received a median of three therapies prior to venetoclax; 40% were BTKi naïve (n = 130), and 81% were idelalisib naïve (n = 263). ORR to BTKi was 84% (n = 44) in BTKi-naïve patients versus 54% (n = 30) in BTKi-exposed patients. We demonstrate therapy selection following venetoclax requires prior novel agent exposure consideration and discontinuation reasons. Conclusions: For BTKi-naïve patients, selection of covalently binding BTKis results in high ORR and durable remissions. For BTKi-exposed patients, covalent BTK inhibition is not effective in the setting of BTKi resistance. PI3Kis following venetoclax do not appear to result in durable remissions. We conclude that BTKi in naïve or previously responsive patients and cellular therapies following venetoclax may be the most effective strategies. See related commentary by Rogers, p. 3501

CART cell therapy has changed the treatment landscape for relapsed/refractory aggressive lymphomas. In this article, we review the CART constructs most studied in lymphoma and their applicability.Results of ZUMA-1, JULIET and TRANSCEND trials will be reviewed. Real-world data will also be reviewed.CART cell therapy is evolving and becoming safer. Increased uptake of this modality outside of clinical trials is expected.

7509 Background: Early results from ELEVATE-TN (NCT02475681) at a median follow-up of 28.3 mo demonstrated superior efficacy of acalabrutinib (A) ± obinutuzumab (O) compared with O + chlorambucil (Clb) in patients (pts) with treatment-naïve (TN) chronic lymphocytic leukemia (CLL) (Sharman et al. Lancet 2020;395:1278-91). Results from a 4-year update are reported here. Methods: Pts received A±O or O+Clb. Crossover to A monotherapy was permitted in pts who progressed on O+Clb. Investigator-assessed (INV) progression-free survival (PFS), INV overall response rate (ORR), overall survival (OS), and safety were evaluated. Results: 535 pts (A+O, n=179; A, n=179; O+Clb, n=177) were randomized with a median age of 70 y; 63% had unmutated IGHV and 9% del(17p). At a median follow-up of 46.9 mo (range, 0.0–59.4; data cutoff: Sept 11, 2020), the median PFS was not reached (NR) for A+O and A pts vs 27.8 mo for O+Clb pts (both P

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma (NHL) that accounts for ∼6% of NHL cases in the USA [1]. Median overall survival (OS), now ∼4–5 years, has improved substantiall...

Escalating doses of bortezomib with high-dose melphalan was evaluated as as a conditioning regimen for autologous stem cell transplantation (ASCT) in patients with relapsed or refractory multiple myeloma (MM). MM patients with less than a partial remission (PR) (or 50% reduction) compared to their pretransplantation paraprotein parameters after a prior ASCT with melphalan conditioning, or who were in relapse after a prior autologous transplantation, were eligible for study. Bortezomib was dose escalated in steps of 1, 1.3, and 1.6 mg/m2 (3 × 3 design) on days −4 and −1 before transplantation with melphalan 200 mg/m2 given on day −2. Thirty-two patients were enrolled: 12 in the phase I dose escalation phase and an additional 20 in phase II to gain additional experience with the regimen. Twenty-four (75%) patients were Durie Salmon stage III, and 12 (37.5%) had >2 prior lines of therapy. The overall response rate (≥PR) was 44% with 22% complete remission. Two-year overall survival and progression-free survival were 76% and 39%, respectively, with a median follow-up of 31.7 months. The most common grade 3 and 4 nonhematologic adverse events were neutropenic fever (25%), nausea (18.8%), and mucositis (9.4%). Serious adverse events included intensive care unit admission (9.4%), seizure (3.1%), prolonged diarrhea (3.1%), and Guillain-Barre syndrome (3.1%). Two patients (6%) died of sepsis. There was no emergent peripheral neuropathy nor increase in any pre-existing peripheral neuropathy. The addition of bortezomib to melphalan as conditioning for salvage ASCT was well tolerated. More importantly, it can provide durable remission for patients who have a suboptimal response to prior single-agent melphalan conditioning for ASCT, without requiring a reduction in the dose of melphalan. Larger randomized prospective studies to determine the effect of combination conditioning are being conducted.

B-cell receptor kinase inhibitor (KI) therapy represents a paradigm shift in chronic lymphocytic leukemia (CLL) management, but data on practice patterns after KI discontinuation and optimal sequencing are limited. We conducted a multicenter, retrospective, comprehensive analysis on 178 patients with CLL (ibrutinib = 143; idelalisib = 35) who discontinued KI therapy. We examined responses, toxicity, post-KI therapies, and overall survival (OS). Patients had a median of 3 prior therapies (range 0-11); del17p (34%), p53 mutation (27%), del11q (33%), and complex karyotype (29%). Overall response rate (ORR) to first KI was 62% (complete response 14%). The most common reasons for KI discontinuation were toxicity (51%), CLL progression (29%), and Richter transformation (RT) (8%). Median progression-free survival (PFS) and OS from KI initiation were 10.5 and 29 months, respectively. Notably, initial KI choice did not impact PFS or OS; however, RT portended significantly inferior OS (P = .0007). One hundred fourteen patients received subsequent salvage therapy following KI discontinuation with an ORR to subsequent KI at 50% and a median PFS of 11.9 months. Median PFS in KI-intolerant patients treated with an alternate KI was not reached vs 7 months for patients with CLL progression. In summary, these data demonstrate that toxicity was the most common reason for KI discontinuation, that patients who discontinue KI due to toxicity can respond to an alternate KI, and that these responses may be durable. This trial was registered at www.clinicaltrials.gov as #NCT02717611 and #NCT02742090.

Background: Acalabrutinib is a highly selective, covalent irreversible Bruton tyrosine kinase inhibitor with minimal activity against other kinases. Acalabrutinib has demonstrated durable responses as a single agent or combined with O in treatment-naïve (TN) CLL. Here, interim results are presented for the multicenter, open-label Phase 3 ELEVATE-TN study (NCT02475681), which evaluated the efficacy and safety of acalabrutinib + O vs acalabrutinib alone vs O + Clb in pts with TN CLL. Methods: Eligible pts had TN CLL requiring treatment per iwCLL criteria and were aged ≥65 y or 6, creatinine clearance Results: From 9/14/2015-2/8/2017, 535 pts were randomized to the acalabrutinib + O (n=179), acalabrutinib (n= 179), or O + Clb (n=177) arms. The median age was 70 y (range, 41-91); 69% had high- and 12% had very high-risk CLL IPI scores. At a median follow-up of 28 mo, acalabrutinib + O significantly prolonged PFS vs O + Clb (median not reached [NR] vs 22.6 mo; HR 0.10, 95% CI 0.06-0.18, P IRC-assessed ORR was higher with acalabrutinib + O (94%; 95% CI, 89.3%-96.5%) vs O + Clb (79%; 95% CI, 71.9%-83.9%; P The median treatment duration was 27.7 mo for acalabrutinib + O (range, 2.3-40.3) and acalabrutinib (range, 0.3-40.2) and 5.6 mo (range, 0.9-7.4) for O + Clb. Common adverse events (AEs) are shown in the Table. AEs were similar between the acalabrutinib-containing arms. Infusion reactions were less frequent with acalabrutinib + O (13%) than with O + Clb (40%). AEs led to treatment discontinuation in 20 pts (11%) on acalabrutinib + O, 16 pts (9%) on acalabrutinib, and 25 pts (14%) on O + Clb. With >2 y of follow-up, 79.3% of pts in both the acalabrutinib-containing arms remain on single-agent acalabrutinib. AEs of interest (acalabrutinib + O or acalabrutinib vs O + Clb) were atrial fibrillation (any grade: 3% or 4% vs 1%), bleeding (any grade/Grade ≥3: 43%/2% or 39%/2% vs 12%/0%), and hypertension (Grade ≥3: 3% or 2% vs 3%). Conclusions: Acalabrutinib + O and acalabrutinib monotherapy significantly improved PFS vs O + Clb, with tolerable safety in pts with TN CLL. Despite cross over for disease progression in the O + Clb arm, a trend toward improved OS was observed in both acalabrutinib arms, though longer follow-up is needed. Disclosures Sharman: AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; Acerta: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Research Funding. Banerji:CIHR: Research Funding; LLSC: Research Funding; Research Manitoba: Research Funding; CCMF: Research Funding; CancerCare Manitoba/University of Manitoba: Employment; CAPhO: Honoraria; BIOGEN: Other: Licensing fee; Dana-Farber Cancer Institute: Other: Licencing fee; Gilead: Consultancy, Honoraria, Research Funding; Astra-Zeneca: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Roche: Honoraria, Licensing fee, Research Funding; Abbvie: Consultancy, Honoraria. Herishanu:Janssen: Honoraria; AbbVie: Honoraria; Roche: Honoraria. Munir:Gilead: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Roche: Honoraria; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sunesis: Consultancy; Pharmacyclics: Other: TBC; Acerta: Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria; AbbVie: Honoraria. Walewska:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Travel grant, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Other: Travel grant, Speakers Bureau; Takeda: Other: Travel grant; Novartis: Other: travel grant. Follows:Abbvie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau. Karlsson:Skane University Hospital: Employment. Ghia:AbbVie: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria; Juno/Celgene: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy; ArQule: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Dynamo: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Corbett:Celgene: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Tauranga Hospital: Employment; Pathlab Waikato: Equity Ownership. Walker:Peninsula Health (public hospital): Employment; Alfred health (public hospital): Employment; Roche: Other: Travel grant. Jurczak:Incyte: Research Funding; Takeda: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Research Funding; Roche: Research Funding; Gilead: Research Funding; Celgene: Research Funding; MorphoSys: Research Funding; Celtrion: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Research Funding. Salles:Epizyme: Consultancy, Honoraria; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Other: Educational events. Janssens:Novartis: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Celgene: Speakers Bureau; abbvie: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; idem consultancy: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau. Cymbalista:AstraZeneca: Honoraria; Janssen: Honoraria; Sunesis: Research Funding; Roche: Research Funding; Gilead: Honoraria; Abbvie: Honoraria. Wierda:Juno Therapeutics: Research Funding; Janssen: Research Funding; Cyclcel: Research Funding; KITE pharma: Research Funding; Loxo Oncology Inc.: Research Funding; Genentech: Research Funding; Xencor: Research Funding; Acerta Pharma Inc: Research Funding; Pharmacyclics LLC: Research Funding; Sunesis: Research Funding; AbbVie: Research Funding; Miragen: Research Funding; Oncternal Therapeutics Inc.: Research Funding; Gilead Sciences: Research Funding; GSK/Novartis: Research Funding. Coutre:Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Acerta: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Research Funding; BeiGene: Other: Travel, Accommodations, Expenses & Data Safety Monitoring Committee; Genentech: Consultancy. Pagel:AstraZeneca: Consultancy; Gilead Sciences: Consultancy; Pharmacyclics: Consultancy. Skarbnik:Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Verastem Oncology: Honoraria, Research Funding, Speakers Bureau; Kite Pharma: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Acerta: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; CLL Society: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Speakers Bureau; Novartis: Speakers Bureau. Kamdar:AstraZeneca: Consultancy; University of Colorado: Employment; Celgene: Consultancy; Seattle Genetics: Speakers Bureau; Pharmacyclics: Consultancy. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Izumi:AstraZeneca: Equity Ownership; Acerta Pharma: Employment, Equity Ownership, Patents & Royalties: Acalabrutinib patents. Munugalavadla:Acerta Pharma: Employment; Gilead Sciences: Equity Ownership; AstraZeneca: Equity Ownership. Patel:Acerta Pharma: Employment, Equity Ownership; AstraZeneca: Equity Ownership. Wang:Acerta Pharma: Employment; AstraZeneca: Equity Ownership. Wong:Acerta Pharma: Employment. Byrd:Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Acerta: Research Funding; Acerta: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents & Royalties: OSU-2S; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; BeiGene: Research Funding; BeiGene: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau.

Introduction In clinical practice, a hematopoietic progenitor cell (HPC) dose of 2 million CD34+ cells/kg is the desired minimum needed for timely neutrophil and platelet (PLT) engraftment in autologous hematopoietic cell transplantation (HCT). Patients frequently receive higher HPC doses with the median pre-cryopreservation dose at our center being 5 million CD34+ cells/kg adjBW25%. Cryopreservation (CP) and thawing leads to cell loss through mechanisms including activation of the caspase pathway. The degree of loss in post-CP HPC doses can range from 20 to 85%; hence the cell dose that is able to effectuate engraftment is determined by the percentage of surviving cells in the initial pre-CP cell dose. This effective residual vital dose (ERVD) is the product of the pre-CP cell dose and the post thaw viability percentage. Objective Correlate viability, HPC cell dose and the ERVD to engraftment. Method We conducted a retrospective review of autologous HCT patients at our center to correlate the ERVD with engraftment. Twenty-five patients, ages 32 to 76, receiving 27 transplants had HPC infusions during 1 or 2 sessions within 3 days of each other. Diagnoses were multiple myeloma (MM) (n=20) and lymphoma (n=7). Engraftment of neutrophils and PLTs was defined using CIBMTR definitions. Viability was assessed by 7AAD on CD34+ cells. Data was analyzed with Excel Correlation Function which calculates the Pearson Product-Moment Correlation Coefficient for 2 sets of values. Results The median neutrophil and PLT engraftment times were 11 and 16.5 days, respectively. Correlation of the HPC dose of the total population with neutrophil engraftment data, revealed the r value to be -0.31 for all patients, -0.20 for lymphoma patients, and -0.32 for MM patients. Cell dose correlation with PLT engraftment revealed the r value to be -0.43 for the total population (Figure 1), -0.52 for the lymphoma subset, and -0.55 for the MM subset. We found a moderately strong correlation of ERVD with PLT engraftment with an r value of -0.56 for the entire population, i.e. as ERVD increased, time to PLT engraftment decreased (Figure 2). When separated by diagnosis (MM vs lymphoma) the ERVD correlated moderately with PLT engraftment, r value of -0.57 amongst the MM subset and -0.88 for the lymphoma subset (Figure 3). Neutrophil engraftment had a weaker correlation with the ERVD, r value of -0.33 for the entire population, -0.41 for the MM subset, and -0.68 for the lymphoma subset. Conclusion Based on our data, the ERVD has a moderately strong correlation with PLT and neutrophil engraftment in a population of MM and lymphoma patients undergoing autologous HCT. The correlation was stronger for PLT engraftment and strongest amongst patients with lymphoma. To achieve our median engraftment times for neutrophils and PLTs the optimal ERVD of approximately 3 Million CD34/Kg adjBW25% is suggested.

Duvelisib (also known as IPI-145) is an oral, dual inhibitor of phosphatidylinositol 3-kinase δ and γ (PI3K-δ,γ) being developed for treatment of hematologic malignancies. PI3K-δ,γ signaling can promote B-cell proliferation and survival in clonal B-cell malignancies, such as chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). In a phase 1 study, duvelisib showed clinically meaningful activity and acceptable safety in CLL/SLL patients. We report here the results of DUO, a global phase 3 randomized study of duvelisib vs ofatumumab monotherapy for patients with relapsed or refractory (RR) CLL/SLL. Patients were randomized 1:1 to oral duvelisib 25 mg twice daily (n = 160) or ofatumumab IV (n = 159). The study met the primary study end point by significantly improving progression-free survival per independent review committee assessment compared with ofatumumab for all patients (median, 13.3 months vs 9.9 months; hazard ratio [HR] = 0.52; P < .0001), including those with high-risk chromosome 17p13.1 deletions [del(17p)] and/or TP53 mutations (HR = 0.40; P = .0002). The overall response rate was significantly higher with duvelisib (74% vs 45%; P < .0001) regardless of del(17p) status. The most common adverse events were diarrhea, neutropenia, pyrexia, nausea, anemia, and cough on the duvelisib arm, and neutropenia and infusion reactions on the ofatumumab arm. The DUO trial data support duvelisib as a potentially effective treatment option for patients with RR CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02004522.

Clinical trials that led to ibrutinib’s approval for the treatment of chronic lymphocytic leukemia showed that its side effects differ from those of traditional chemotherapy. Reasons for discontinuation in clinical practice have not been adequately studied. We conducted a retrospective analysis of chronic lymphocytic leukemia patients treated with ibrutinib either commercially or on clinical trials. We aimed to compare the type and frequency of toxicities reported in either setting, assess discontinuation rates, and evaluate outcomes. This multicenter, retrospective analysis included ibrutinib-treated chronic lymphocytic leukemia patients at nine United States cancer centers or from the Connect® Chronic Lymphocytic Leukemia Registry. We examined demographics, dosing, discontinuation rates and reasons, toxicities, and outcomes. The primary endpoint was progression-free survival. Six hundred sixteen ibrutinib-treated patients were identified. A total of 546 (88%) patients were treated with the commercial drug. Clinical trial patients were younger (mean age 58 versus 61 years, P=0.01) and had a similar time from diagnosis to treatment with ibrutinib (mean 85 versus 87 months, P=0.8). With a median follow-up of 17 months, an estimated 41% of patients discontinued ibrutinib (median time to ibrutinib discontinuation was 7 months). Notably, ibrutinib toxicity was the most common reason for discontinuation in all settings. The median progression-free survival and overall survival for the entire cohort were 35 months and not reached (median follow-up 17 months), respectively. In the largest reported series on ibrutinib- treated chronic lymphocytic leukemia patients, we show that 41% of patients discontinued ibrutinib. Intolerance as opposed to chronic lymphocytic leukemia progression was the most common reason for discontinuation. Outcomes remain excellent and were not affected by line of therapy or whether patients were treated on clinical studies or commercially. These data strongly argue in favor of finding strategies to minimize ibrutinib intolerance so that efficacy can be further maximized. Future clinical trials should consider time-limited therapy approaches, particularly in patients achieving a complete response, in order to minimize ibrutinib exposure.

Introduction: Prior to effective novel agent (NA) approval for CLL, alloHSCT was recommended for CLL patients (pts) with early relapse/refractory disease after purine-analogs or deletion 17p (del17p) or TP53 mutation (TP53mut) based on expert consensus and retrospectively demonstrated overall survival (OS) advantage. Since 2014, approvals of ibrutinib (ibr), venetoclax (ven), and PI3K inhibitors (PI3Ki) have led to fewer alloHSCT for CLL. While NAs are indisputably effective, many pts will eventually progress through all available NAs. In the absence of data-driven consensus regarding role of alloHSCT for CLL, decision about proceeding to transplant is currently based on disease and transplant risk, response to NAs, and pt preference. This study of CLL pts who underwent alloHSCT following NA therapy (tx) aimed to help define the role of this potentially curative modality in the era of NAs. Methods: This multicenter, retrospective cohort study examined CLL pts who underwent alloHSCT following treatment with ≥ 1 NA, including baseline clinical, prognostic, and transplant characteristics, tx preceding alloHSCT, transplant outcomes, and tx following alloHSCT. Complex karyotype (CK) and CLL status [complete remission (CR), partial remission (PR), stable disease (SD), and progression of disease (POD)] were defined per iwCLL criteria (Hallek, et al. Blood 2018). Univariate analyses utilizing COX regression evaluated association between pre-alloHSCT factors and progression free survival (PFS). PFS, OS, and non-relapse mortality (NRM) were estimated using Kaplan Meier and life table methods. Other statistics were descriptive. Results: 69 pts with CLL underwent alloHSCT following ≥ 1 NA across 14 US and EU centers, including 6 pts with Richter's transformation (RT) prior to alloHSCT. Table 1 describes baseline characteristics. Prior to alloHSCT, 78% received ibr (n=53), 39% ven (n=25), 20% PI3Ki (n=13), and 36% ≥ 2 NAs. 90% (n=62) received a NA immediately preceding alloHSCT [n=32 ibr (16% CR, 75% PR, 9% SD/POD), n=25 ven (52% CR, 40% PR, 8% SD/POD), 4 PI3Ki (75% PR, 25% SD/POD), 1 IMiD]. With a median (med) follow up 28 months (mo; range 1.2 -85), med PFS and OS from alloHSCT for the entire cohort were not reached (Figure 1A, B). PFS and OS for pts with CLL (excluding RT pts) from alloHSCT were 60% and 82% at 24 mo respectively. Poor risk disease characteristics (TP53mut, del17p, CK), prior NA exposure (ibr, ven, PI3Ki, ≥2 NAs), and transplant characteristics (matched (8/8) vs. mismatched ( To guide decision making about timing of alloHSCT, we examined pts who received 1 (n=44) vs. ≥2 (n=25) NAs. These groups were similar in terms of poor risk features (del 17p 48% vs. 38%, TP53mut 44% vs. 40%, del11q 21% vs. 36%, CK 41% vs. 54%), transplant risk (med age 60 for both groups, med HSCT-CI 0 vs. 1, matched donor 86% vs. 71%), and disease status prior to alloHSCT (CR 25% vs. 40%, PR 66% vs. 48%, SD/POD 9% vs. 12%). PFS was similar for those exposed to 1 vs. ≥ 2 NAs (Figure 1C). Disease status at time of alloHSCT and hematopoietic cell transplantation-specific comorbidity index (HCT-CI) significantly impacted PFS (Figure 1D, E). Conclusions: In the largest series of alloHSCT following NAs, data demonstrate that alloHSCT remains a viable curative strategy that can overcome adverse CLL characteristics including TP53 disruption and CK. As many pts treated with ibr and/or ven will progress or be intolerant, alloHSCT should be included in treatment algorithms for appropriate candidates. These data suggest that exposure to 1 vs. ≥2 prior NAs did not impact outcomes, though disease status at time of alloHSCT and HCT-CI are important predictors of PFS. Therefore, decision about proceeding to alloHSCT should consider comorbidities and current depth of response, as well as anticipated depth of response with the therapeutic options remaining. These data may significantly add to development of evidence-based guidelines for alloHSCT in the era of NAs. Figure 1 Disclosures Roeker: AbbVie: Equity Ownership; Abbott Laboratories: Equity Ownership. Brown:TG Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Sun Pharmaceuticals: Research Funding; Janssen: Honoraria; Teva: Honoraria; Morphosys: Other: Data safety monitoring board; Invectys: Other: Data safety monitoring board; Octapharma: Consultancy; Dynamo Therapeutics: Consultancy; Sunesis: Consultancy; Juno/Celgene: Consultancy; Genentech/Roche: Consultancy; Gilead: Consultancy, Research Funding; Catapult Therapeutics: Consultancy; AbbVie: Consultancy; Acerta Pharma: Consultancy; AstraZeneca: Consultancy; BeiGene: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Loxo: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Pharmacyclics: Consultancy. Dreger:AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy; AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; Neovii, Riemser: Research Funding. Eyre:Roche: Honoraria; Abbvie: Honoraria, Other: Travel to Conferences; Takeda: Other: Travel to Conferences ; Gilead: Consultancy, Other: Research support, Speakers Bureau; Janssen: Honoraria, Other: Travel to Conferences . Brander:AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria; Tolero: Research Funding; Acerta: Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Research Funding; Novartis: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; BeiGene: Research Funding; DTRM Biopharma: Research Funding; MEI: Research Funding. Skarbnik:Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Verastem Oncology: Honoraria, Research Funding, Speakers Bureau; Kite Pharma: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Acerta: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; CLL Society: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Speakers Bureau; Novartis: Speakers Bureau. Coombs:H3 Biomedicine: Research Funding. Orchard:Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Unrestricted educational award for regional meetings ; Incyte: Other: Unrestricted educational award for regional meetings ; Adienne: Other: Unrestricted educational award for regional meetings . Sauter:Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Kite/Gilead: Consultancy; Precision Biosciences: Consultancy; Genmab: Consultancy; GSK: Consultancy. Giralt:Johnson & Johnson: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy; Kite: Consultancy; Amgen: Consultancy, Research Funding; Actinium: Consultancy, Research Funding; Novartis: Consultancy; Miltenyi: Research Funding; Takeda: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy. Perales:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Omeros: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria; Medigene: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Kyte/Gilead: Research Funding; Nektar Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Miltenyi: Research Funding; NexImmune: Membership on an entity's Board of Directors or advisory committees; MolMed: Membership on an entity's Board of Directors or advisory committees. Mato:Celgene: Consultancy; AbbVie: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; LOXO: Consultancy, Research Funding; DTRM Biopharma: Research Funding; Genentech: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Gilead: Research Funding; Acerta: Consultancy; Janssen: Consultancy; AstraZeneca: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Johnson & Johnson: Consultancy, Research Funding.

BACKGROUND Novel agents have changed the treatment landscape in chronic lymphocytic leukemia (CLL), however little has been reported about real-world treatment sequence patterns and associated outcomes post-introduction of novel agents. Studies have demonstrated that venetoclax is effective for patients (pts) who have discontinued ibrutinib, however treatments and outcomes post-venetoclax discontinuation remain unclear. The objective of this study was to examine real-world treatment sequence patterns post-introduction of novel agents and specifically understand treatment sequencing following venetoclax. METHODS The CLL Collaborative Study of Real-World Evidence (CORE) is a retrospective, multicenter, collaborative observational study of pts with CLL/small lymphocytic leukemia (SLL). For this analysis, adult pts were eligible for inclusion if they started therapy for CLL/SLL in the relapsed/refractory setting after February 12, 2014 (FDA approval date of first novel agent for CLL/SLL). Interim data are presented; data collection for this analysis is ongoing and is expected to be completed by October 31, 2019. Treatment sequences were characterized specifically focusing on treatment sequencing following venetoclax and other novel agents (i.e., BCRi: e.g., ibrutinib, idelalisib or acalabrutinib). Clinical response, as assessed by physician, was also reported from medical charts (iwCLL criteria were provided as a reference only). RESULTS Of the 267 pts available at the time of interim data analysis, 231 pts (87%) received a novel agent in at least one line of therapy (first-line: 35 pts [15%]; second-line: 133 pts [58%]; third-line or later: 63 pts [27%]). Among novel agents, ibrutinib was the most commonly used first novel agent for 198 pts (86%) followed by venetoclax for 18 pts (8%) and idelalisib for 12 pts (5%). Of those 267 pts, 143 pts (54%) received chemotherapy/chemoimmunotherapy (CT/CIT) followed by a novel agent; 63 pts (24%) received a novel agent followed by a novel agent; 17 (7%) received a novel agent followed by CT/CIT; and 47 (18%) received a CT/CIT followed by CT/CIT. At the time of this interim data cut there were 220 pts (82%) who received BCRi-based regimens (first-line: 33 pts [15%]; second-line: 123 pts [56%]; third-line or later: 64 pts [29%]) and 62 pts (23%) who received venetoclax-based regimens (first-line: 2 pts [3%]; second-line: 22 pts [36%]; third-line or later: 38 pts [61%]). Of the 220 pts who received BCRi-based regimens, 50 (23%) achieved complete remission (CR) and 83 (38%) achieved partial remission (PR) (responses based on physician assessment). Of the 220 pts, 88 (40%) went on to receive a subsequent line of therapy. The most common subsequent treatments administered were venetoclax containing regimens (n= 34, 39%). Of the 88 pts who received a subsequent line of therapy after BCRi-based regimens, 22 pts (25%) achieved CR and 24 pts (27%) achieved PR. Of the 62 pts who received venetoclax-based regimens, 20 pts (32%) achieved CR and 14 pts (23%) achieved PR. Of the 62 pts, 15 pts (24%) went on to receive a subsequent line of therapy. The most common subsequent treatment administered were BCRi containing regimens (n= 10, 67%) primarily ibrutinib-based. Of the 15 pts receiving a subsequent line of therapy after venetoclax-based regimens, 3 pts (20%) achieved CR and 4 pts (27%) achieved PR. While preliminary results are encouraging, further data collection efforts are ongoing and will be included for presentation to confirm the results and outcomes associated with different sequencing options. CONCLUSIONS The treatment paradigm is evolving with the introduction of novel agents. Results from this study will provide a baseline description of treatment sequence patterns enabling clinicians to benchmark the impact of the introduction of novel agents and associated outcomes. Early evidence from these results also suggests that novel agents are most commonly introduced during second line treatment and that other novel agents, including ibrutinib, following venetoclax treatment are being utilized in the real-world settings. Table. Disclosures Mato: Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; DTRM Biopharma: Research Funding; Johnson & Johnson: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; Acerta: Consultancy; Janssen: Consultancy; Gilead: Research Funding; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Celgene: Consultancy. Sail:AbbVie: Employment, Other: may hold stock or stock options. Yazdy:Genentech: Research Funding; Octapharma: Consultancy; Abbvie: Consultancy; Bayer: Honoraria, Speakers Bureau. Hill:Amgen: Research Funding; Seattle Genetics: Consultancy, Honoraria; Celegene: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Research Funding; Kite: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; TG therapeutics: Research Funding; Takeda: Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Shadman:Bigene: Research Funding; TG Therapeutics: Research Funding; AbbVIe: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Research Funding; AstraZeneca: Consultancy; Sound Biologics: Consultancy; Pharmacyclics: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Atara: Consultancy; Verastem: Consultancy; Mustang Biopharma: Research Funding; Gilead: Research Funding; Merck: Research Funding; Acerta: Research Funding; Emergent: Research Funding; Celgene: Research Funding; Sunesis: Research Funding. Manzoor:AbbVie: Employment, Other: and may hold stock or stock options. Tuncer:Abbvie: Membership on an entity's Board of Directors or advisory committees; 2018 Steering Committee: Other: reimbursement for travel to the steering committee at ASH. Allan:Janssen: Consultancy, Honoraria; Acerta Pharma: Consultancy; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics LLC, an AbbVie company: Consultancy; Verastem Oncology, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy; Sunesis Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ujjani:PCYC: Research Funding; Pharmacyclics: Honoraria; AbbVie: Honoraria, Research Funding; Genentech: Honoraria; Atara: Consultancy; Astrazeneca: Consultancy; Gilead: Consultancy. Sharmokh:AbbVie: Employment, Other: may hold stock or stock options. Jiang:AbbVie: Employment, Other: and may hold stock or stock options. Pena:AbbVie: Employment, Other: and may hold stock or stock options. Marshall:AbbVie: Employment, Other: and may hold stock or stock options. Nielsen:AbbVie: Employment, Other: and may hold stock or stock options. Barr:Janssen: Consultancy; Astra Zeneca: Consultancy, Research Funding; Verastem: Consultancy; Genentech: Consultancy; Seattle Genetics: Consultancy; Merck: Consultancy; Celgene: Consultancy; TG Therapeutics: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie company: Consultancy, Research Funding; AbbVie: Consultancy; Gilead: Consultancy. Brown:Pfizer: Consultancy; Pharmacyclics: Consultancy; Sunesis: Consultancy; Teva: Honoraria; TG Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Sun: Research Funding; Sun Pharmaceuticals, Inc: Research Funding; Morphosys: Other: Data safety monitoring boards ; Acerta Pharma: Consultancy; AstraZeneca: Consultancy; BeiGene: Consultancy; Catapult Therapeutics: Consultancy; Dynamo Therapeutics: Consultancy; Genentech/Roche: Consultancy; Gilead: Consultancy, Research Funding; Invectys: Other: other; Janssen: Honoraria; Kite: Consultancy, Research Funding; Loxo: Consultancy, Research Funding; Novartis: Consultancy; Octapharma: Consultancy. Schuh:Pharmacyclics: Consultancy, Speakers Bureau; AbbVie: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Janssen: Speakers Bureau; Verastem: Speakers Bureau; Kite: Speakers Bureau; Gilead: Speakers Bureau; Seattle Genetics: Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau; Bristol-Myers Squibb: Research Funding. Eyre:Janssen: Honoraria, Other: travel support; Gilead: Honoraria, Other: travel support; AbbVie: Honoraria, Other: travel support. Wierda:Pharmacyclics LLC: Research Funding; Juno Therapeutics: Research Funding; Gilead Sciences: Research Funding; Miragen: Research Funding; Cyclcel: Research Funding; Oncternal Therapeutics Inc.: Research Funding; GSK/Novartis: Research Funding; Genentech: Research Funding; Xencor: Research Funding; Acerta Pharma Inc: Research Funding; KITE pharma: Research Funding; Sunesis: Research Funding; Loxo Oncology Inc.: Research Funding; Janssen: Research Funding; AbbVie: Research Funding. Skarbnik:Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Verastem Oncology: Honoraria, Research Funding, Speakers Bureau; Kite Pharma: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Acerta: Research Funding; Genentech: Honoraria, Speakers Bureau; CLL Society: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Speakers Bureau; Novartis: Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Roeker:Abbott Laboratories: Equity Ownership; AbbVie: Equity Ownership. Bannerji:Gilead: Other: travel support; Celgene: Consultancy; Celgene: Consultancy; Regeneron Pharmaceuticals, Inc.: Consultancy, Other: travel support, Research Funding; Merck: Other: travel support, Patents & Royalties: IP rights; Regeneron Pharmaceuticals, Inc.: Consultancy, Other: travel support, Research Funding; Pharmacyclics: Other: travel support; AbbVie, Inc: Consultancy; Pharmacyclics: Other: travel support; Gilead: Other: travel support; AbbVie, Inc: Consultancy, travel support; Merck: Other: travel support, Patents & Royalties: IP rights. Pauff:AbbVie Inc: Employment, Other: may own stock or stock options. Schuster:Novartis, Nordic Nanovector, and Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: a patent (with royalties paid to Novartis) on combination therapies of CAR and PD-1 inhibitors.; Novartis, Celgene, Genentech, Merck, Pharmacyclics, Acerta, and Gilead: Other: Grants, Research Funding; Nordic Nanovector, Pfizer, AstraZeneca, Loxo Oncology, Acerta, and Celgene: Honoraria. Follows:Roche: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Honoraria, Speakers Bureau. Cheson:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbios: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Portola: Research Funding; Gilead: Research Funding; Epizyme: Research Funding. Eichhorst:Gilead Sciences, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BeiGene: Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; ArQule: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Brander:Genentech: Consultancy, Honoraria, Research Funding; DTRM Biopharma: Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Research Funding; BeiGene: Research Funding; Novartis: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; AbbVie: Consultancy, Honoraria, Research Funding; Acerta: Research Funding; Tolero: Research Funding; Teva: Consultancy, Honoraria; MEI: Research Funding. Pivneva:AbbVie: Other: employee of Analysis Group, Inc., which has received consultancy fees from AbbVie. Lamanna:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Verastem: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Bei-Gene: Research Funding; TG Therapeutics: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Roche-Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction: Acalabrutinib (acala) is an irreversible, second generation Bruton tyrosine kinase inhibitor (BTKi) approved by the FDA for the treatment of relapsed/refractory (R/R) mantle cell lymphoma, and is in advanced stages of clinical testing for front line (FL) and R/R CLL (Byrd NEJM, Wang NEJM). Ibrutinib (ibr) is a well-established and potent treatment for CLL; however, discontinuation due to intolerance precludes a significant number of patients (pts) in clinical practice from long-term benefit of this targeted therapy (Mato et al Blood 2016, Follows BJH 2017). Acala inhibits BTK more selectively than ibr, and while demonstrating impressive activity, may result in significantly less off-target adverse events (AEs). Although not yet FDA approved, it is being increasingly used in CLL pts with ibr-intolerance or cardiovascular or hematologic comorbidities (atrial fibrillation (AF), hypercoagulable state on long-term anticoagulation, etc.) to potentially avoid ibr-related toxicities. The increasing use of acala in clinical practice provides an opportunity to address various knowledge gaps. Therefore, we conducted a multi-institutional, retrospective analysis in CLL pts treated with acala in the real-world setting. We aimed to report and analyze the main reasons for starting acala, its safety, efficacy, outcome and sequencing. Patients and Methods: This multi-institutional, retrospective analysis included acala-treated CLL pts at 9 US cancer centers. We analyzed and described prior treatments, dosing of acala, discontinuations, toxicities and outcomes. The primary endpoint was progression-free survival (PFS) as predicted by the Kaplan Meier method. Results: 69 CLL pts treated with acala (off clinical trials) were identified. Baseline characteristics are described in Table 1. Median age was 70 years (range 51-89) and 6 (9%) and 63 (91%) pts received acala in the FL and R/R settings, respectively. Of the R/R pts, 49 (78%) had received a prior BTKi, 11 (17%) a phosphoinositide 3-kinase inhibitor (PI3Ki), 14 (22%) venetoclax, 18 (29%) bendamustine, and 17 (27%) fludarabine. Median time from diagnosis of CLL to starting acala was 79.5 months. Most common reasons for choosing acala were prior intolerance to other agents in 47 (68%), disease progression on the prior line of therapy in 19 (28%) and concern for intolerance to other therapies due to age/comorbidities in 9 (13%). Prior intolerance to ibr was the reason for starting acala in 46 (98%) of the intolerant pts; the most common AEs leading to discontinuation of ibr were rash in 10 (22%), AF/flutter in 8 (17%), arthralgia in 8 (17%), bleeding in 6 (13%), infection in 6 (13%) and fatigue in 6 (13%). Almost all pts (99%) started on acala 100 mg orally twice daily, with dose reductions required in 5 (7%). The most common toxicities on acala were fatigue in 9 (13%), infection in 9 (13%), diarrhea/colitis in 7 (10%), nausea/vomiting in 6 (9%), headache in 5 (7%), rash in 5 (7%), bleeding in 2 (3%) and AF/flutter in 1 (1%). The median time from the start of acala to an infection was 3 months. With a median follow-up of 5 months, the acala discontinuation rate was estimated to be 19% (13 pts) with median time to discontinuation of 1 month. The main reason for discontinuation was AEs in 8 pts (12%) (no consistent pattern of AEs), all in R/R pts with median time to discontinuation of 3.5 months; 2 others proceeded to CAR T-cell therapy or allogeneic transplant; 2 died of unrelated causes, 1 from progressive disease off acala. Overall response rate (ORR) was 62% (9% CR, 53% PR, number reported = 66), 50% PR in FL (3/6) and 63% (CR 5%, PR 58%, number reported = 60) in R/R pts. The differences likely reflected small numbers and short follow-up. Median PFS and overall survival were not reached (Figs 1a,b). Conclusion: In this group of largely ibr-intolerant pts, the overall acala discontinuation rate was lower than prior reports from clinical trials, although with relatively short follow up. However, discontinuation rate due to AEs appears to be similar to clinical trial data in an ibr-intolerant pt population (Awan Blood Adv, Rogers ICML 2019). These data demonstrate the need for the results of randomized studies, in order to compare the efficacy and AE profile of acala relative to ibr and other novel agents and Disclosures Yazdy: Genentech: Research Funding; Bayer: Honoraria, Speakers Bureau; Octapharma: Consultancy; Abbvie: Consultancy. Mato:Genentech: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Celgene: Consultancy; Johnson & Johnson: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; Acerta: Consultancy; Janssen: Consultancy; Gilead: Research Funding; DTRM Biopharma: Research Funding; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; LOXO: Consultancy, Research Funding. Roeker:AbbVie: Equity Ownership; Abbott Laboratories: Equity Ownership. Ujjani:Gilead: Consultancy; Atara: Consultancy; Genentech: Honoraria; AbbVie: Honoraria, Research Funding; PCYC: Research Funding; Pharmacyclics: Honoraria; PCYC: Research Funding; Pharmacyclics: Honoraria; Astrazeneca: Consultancy. Shadman:TG Therapeutics: Research Funding; Gilead: Research Funding; Merck: Research Funding; Bigene: Research Funding; Celgene: Research Funding; Acerta: Research Funding; Emergent: Research Funding; Sunesis: Research Funding; Mustang Biopharma: Research Funding; Atara: Consultancy; Pharmacyclics: Consultancy, Research Funding; Verastem: Consultancy; AbbVIe: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Research Funding; AstraZeneca: Consultancy; Sound Biologics: Consultancy; ADC Therapeutics: Consultancy. Skarbnik:Genentech: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Acerta: Research Funding; Novartis: Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Verastem Oncology: Honoraria, Research Funding, Speakers Bureau; Kite Pharma: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; CLL Society: Consultancy, Membership on an entity's Board of Directors or advisory committees. Pagel:AstraZeneca: Consultancy; Gilead Sciences: Consultancy; Pharmacyclics: Consultancy. Patel:Sunesis: Consultancy; Pharmacyclics/Janssen: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Genentech: Consultancy, Speakers Bureau. Jacobs:AstraZeneca: Speakers Bureau; Gilead: Consultancy; Genentech: Speakers Bureau; JUNO: Consultancy; TG Therapeutics: Honoraria, Research Funding; AbbVie: Consultancy, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Research Funding, Speakers Bureau. Feldman:Portola Pharma: Research Funding; Roche: Research Funding; Corvus: Research Funding; Eisai: Research Funding; Kyowa Hakko Kirin: Research Funding; Roche: Research Funding; Trillium: Research Funding; Viracta: Research Funding; Pfizer: Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Other: Travel expenses, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Other: Travel expenses, Speakers Bureau; AbbVie: Honoraria, Other: Travel expenses, Speakers Bureau; Amgen: Research Funding; Cell Medica: Research Funding; Kite Pharma: Honoraria, Other: Travel expenses, Speakers Bureau. Goy:University of Nebraska: Research Funding; Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants outside of the submitted work, Research Funding; Hakensackumc: Research Funding; Hackensack University Medical Center, RCCA: Employment; Genentech: Other: Grants outside of the submitted work, Research Funding; Pharmacyclics/Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants outside of the submitted work, Research Funding; Takeda: Other: Grants outside of the submitted work; Astrazenca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants outside of the submitted work; COTA: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Other: leadership role for profit healthcare company; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Coombs:Pharmacyclics: Honoraria; Loxo: Honoraria; H3 Biomedicine: Honoraria; Octopharma: Honoraria; Dedham Group: Consultancy; Cowen & Co.: Consultancy; Medscape: Honoraria; Abbvie: Consultancy; Covance: Consultancy. Lamanna:Celgene: Consultancy; Infinity/ Verastem: Research Funding; Ming: Research Funding; TG Therapeutics: Research Funding; Oncternal: Research Funding. Weiss:TG Therapeutics: Other: family member with employment and equity) . Cheson:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Research Funding; Portola: Research Funding; Kite: Research Funding; Gilead: Research Funding; Epizyme: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbios: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: Acalabrutinib is an irreversible, second generation Bruton tyrosine kinase inhibitor approved by the FDA for the treatment of relapsed/refractory (R/R) mantle cell lymphoma, and is in advanced stages of clinical development testing for front line (FL) and R/R CLL. Although not yet FDA approved, it is being increasingly used in CLL patients in clinical practice. This highlights the necessity to address various knowledge gaps.

Chemoimmunotherapy (CIT) has become a cornerstone in the treatment of patients with chronic lymphocytic leukemia (CLL). The combination of fludarabine, cyclophosphamide and rituximab (FCR) has emerged as the standard of care for therapy of previously untreated patients with CLL who are younger than 65 years and have no significant comorbidities. In this article, we review the role of FCR in the current treatment paradigm for CLL.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is now standard of care for newly diagnosed patients with multiple myeloma (MM) and is used for some forms of non-Hodgkin lymphoma, providing improved outcomes. ASCT has been associated with a high incidence of engraftment syndrome (ES), which clinically presents as skin rashes, diarrhea, non-infectious fevers, and capillary leak syndrome in the peri-engraftment period. ES can be a severe and potentially lethal complication in patients who do not respond to corticosteroid therapy. RATIONALE: Prior to stem cell collection, MM and lymphoma patients are typically exposed to chemotherapy and immunomodulatory agents in order to reduce the cancer cell burden and other drugs to mobilize stem cells. It has been hypothesized that these agents may be involved with ES development in that they can disrupt the balance of immune regulatory and effector cell subsets. OBJECTIVE: To analyze T cell activation/memory and Treg cell compartments as well as classical, intermediate, and non-classical monocytes in the autologous apheresis product of MM and lymphoma patients undergoing ASCT. STUDY DESIGN: Samples were collected under IRB approval from 28 patients undergoing ASCT for the treatment of MM (n=21) or lymphoma (n=7) at the time of peripheral blood stem cell collection (the apheresis product); Peripheral blood mononuclear cells (PBMC) were isolated by sucrose gradient centrifugation and frozen until needed for phenotyping by multi-parametric flow cytometry. MM patients were conditioned for ASCT with melphalan alone (n=14) or in combination with bortezomib (n=7); lymphoma patients received conditioning with BEAM (carmustine, etoposide, cytarabine, and melphalan) chemotherapy. RESULTS: Of the 28 patients undergoing ASCT, 10 (35.7%) developed ES within the first four weeks post-transplantation. We analyzed by flow cytometric phenotyping the following immune cell subsets: overall CD4/CD8 T cells, CD4/CD8 naïve and memory cells, HLA-DR expression on memory T Cells, memory CD4 Tregs, as well as overall classical, intermediate, and non-classical monocytes. The absolute numbers (PBMC conc. (cell/ml of blood) x (% of cells in PBMC/100) and percentage population (# of events in population gate/# of total PBMC events x 100) data were transformed with log and square root functions, respectively. All data were tested for normality with a Shapiro-Wilks online test and p-values were obtained by performing an unpaired Student T-test. From our analysis of the apheresis product, the main cell compartments that were significantly increased in the ES+ group were the % CD8+ T cells [5.41 mean ± 0.51 s.e. vs. 3.34 ± 0.36 (ES-), p=0.003] and naïve CD8+ T cells [3.76 ± 0.56 vs. 1.61 ± 0.18 (ES-), p In the monocyte compartment, the main subset that was significantly increased was the non-classical CD16+CD14low cells in the ES+ group [0.40 ± 0.08 vs. 0.25 ± 0.03 (ES-), p=0.02]. In addition, the % of CD25+ and CD163+ non-classical and intermediate monocytes were favorably increased in the ES+ group (non-classical monocytes, CD25+ [0.14 ± 0.03 vs. 0.07 ± 0.02 (ES-), p=0.03] and CD163+ [0.33 ± 0.06 vs. 0.18 ± 0.02 (ES-), p=0.03]; and for intermediate monocytes, CD25+ [0.44 ± 0.1 vs. 0.22 ± 0.04 (ES-), p=0.02] and CD163+ (p=0.02). No major differences were observed between ES+ and ES- groups for CD64 and PDL-1 expression. CONCLUSIONS: The development of ES correlated with the observation of a significant increase of naïve and activated CD8 T cells in the autologous apheresis product. In contrast, no significant differences were found between the ES+ and ES- groups in the CD4 T cell or memory Treg subsets, suggesting that they do not contribute to the etiology of the syndrome. Moreover, an increased presence of non-classical monocytes with higher expression of both CD163 and CD25 was found, suggesting increased potential for both M2 and M1 activity. Further investigation is needed to determine the implications of these findings for the development of ES. Disclosures Siegel: Merck: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Novartis: Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Biran:BMS: Research Funding; Merck: Research Funding; Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Feldman:Johnson and Johnson: Speakers Bureau; KITE: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau; Portola: Research Funding; Celgene: Speakers Bureau. Skarbnik:Gilead Sciences: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is now the standard of care for newly diagnosed MM and refractory DLBCL patients. However, relapse remains the primary cause of morbidity and mortality, and thus, new therapeutic strategies are required to improve overall survival. In recent years, treatment with immune checkpoint inhibitors Nivolumab (Nivo), an anti-PD1 mAb, or Ipilimumab (Ipi), an anti-CTLA4 mAb, as single agents have achieved durable responses in patients with advanced solid tumors, and may prove to be useful for the treatment of hematological malignancies. RATIONALE: In patients with advanced cancers including melanoma and Hodgkin's lymphoma, combined Nivo/Ipi therapy resulted in superior clinical efficacy compared to monotherapy. The immediate post-ASCT period provides an ideal window to introduce combined therapy because disease burden is at a minimum and the conditioning-induced inflammatory environment may enhance checkpoint inhibition effects on anti-tumor immune responses. OBJECTIVE: To study the Treg and memory T cell compartments in the peripheral blood (PB) of high-risk MM and DLBCL patients, within the first 12 wks post-ASCT, during a Nivo/Ipi treatment regimen. STUDY DESIGN: The interim longitudinal analyses of early Treg and memory T cell profiles was performed on PB sampled from patients up to 12 wks post-ASCT and treated with Nivo + Ipi, with a focus on four patient disease groups: A=de novo DLBCL; B=recurrent high-risk DLBCL; E=de novo high-risk MM; and F=recurrent MM. PB samples obtained from patients at initial screening (PB0) served as a baseline. The MM patients underwent conditioning with CDE or melphalan 200 mg/m2 followed by mobilization with filgrastim, apheresis, and hematopoietic progenitor cell reinfusion. Lymphoma patients were conditioned with BEAM. Starting 2-4 wks later, they were administered double therapy (Ipi 1mg/kg; 6 doses at wks 1, 4, 7, 10, 16, 22 and Nivo 3 mg/kg; 12 doses at wks 1, 4, 7, 10, 12, 14, 16, 18, 20, 22, 24, 26). PB was collected just prior to any treatment at various time points. RESULTS: Table 1 summarizes the mean ± sem % of total lymphocytes for the Treg compartment at all time points. The % of naïve (RO-) Tregs was decreased up to wk 12 in all the groups (A; PB0 0.17; PB12 0.05), (B; PB0 0.16; PB12 0.03), (E; PB0 0.40; PB12 0.02), (F; PB0 0.32; PB12 0.00); and in memory (RO+) Tregs, except for F, (A; PB0 0.86; PB12 0.48), (B; PB0 0.16; PB12 0.03), (E; PB0 1.26; PB12 0.39), (F; PB0 0.32; PB12 0.53). Similar results were observed in the absolute numbers of Tregs for all groups. In the memory T cell compartment, summarized in Table 2, by wk 12, the % effector memory (EM) CD4+ T cells increased in the A and F groups, but were decreased in B and E (A; PB0 4.69; PB12 5.33), (B; PB0 4.12; PB12 2.45), (E; PB0 5.69; PB12 2.99), (F; PB0 3.27; PB12 5.14). In contrast, EM CD8+ T cells in the A and E groups decreased in this compartment (A; PB0 2.91; PB12 1.49) (E; PB0 16.57; PB12 0.46), while the B group markedly increased by wk 12 (B; PB0 0.65; PB12 17.91), and the F group remained equivalent (F; PB0 0.18; PB12 0.24). Moreover, the centralmemory (CM) CD4+ T cell compartment was moderately decreased in all groups, except the F group (A; PB0 2.59; PB12 1.04), (B; PB0 4.12; PB12 2.5), (E; PB0 5.6; PB12 0.82), (F; PB0 1.62; PB12 1.5). Finally, the % of CD4+CCR7+RO-terminally differentiated (TEMRO-) cells was decreased in A, E and F, but not in B, groups (A; PB0 0.80; PB12 0.20), (B; PB0 0.23; PB12 0.26), (E; PB0 1.82; PB12 0.23), (F; PB0 0.66; PB12 0.43). In contrast, the % of CD8+CCR7+RO- TEMRO- cells was increased in B (PB0 1.52; PB12 11.73) and E (PB0 0.76; PB12 2.93), but not in A (PB0 3.12; PB12 2.08) and F (PB0 0.02; PB12 0.0.00) groups. Similar trends were observed with the absolute numbers of subsets. CONCLUSIONS: Combined Nivo + Ipi therapy administered early post-ASCT exhibited a trend of decreased presence of naïve Tregs, in all groups, and memory Tregs in all groups but F by wk 12. In addition, there was an increased trend in the presence of CD8+ EM T cells in group B, and of the CD4+ EM T cells in groups A and F. Increased EM activity could potentially enable the immune system to continue to target tumor cells while in therapy. Finally, there was an increased trend in both CD4+ and CD8+ TEMRO- T cells in group B, which were consistent with the notion of exhaustion of longer surviving EM T cells. Disclosures Munshi: Kite: Speakers Bureau. Atkins:Merck: Consultancy; BMS: Consultancy. Biran:Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Merck: Research Funding; BMS: Research Funding; Amgen: Consultancy, Speakers Bureau. Siegel:Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Novartis: Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Feldman:Portola: Research Funding; Seattle Genetics: Research Funding, Speakers Bureau; Johnson and Johnson: Speakers Bureau; KITE: Speakers Bureau; Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau; Celgene: Speakers Bureau. Skarbnik:Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

Engraftment syndrome (ES) is a frequently occurring complication in patients receiving autologous stem cell transplantation (ASCT) for the treatment of multiple myeloma and various types of non-Hodgkin lymphomas. This clinical entity presents as skin rashes, diarrhea, non-infectious fevers and capillary leak syndrome in the peri-engraftment period coinciding with neutrophil recovery. The etiology and risk factors contributing to the development of ES remain unclear. The goal of the present study was to analyze the cytokine composition of the grafted mobilized peripheral blood stem cell product as well as serum cytokine levels in patients undergoing ASCT for the treatment of multiple myeloma and lymphoma. Cytokines were analyzed in the apheresis stem cell product, as well as patient plasma 1-2 days pre-transplant, 12 days post-transplant, and 2-4 months post-transplant using the Luminex xMAP multiplex cytokine platform. The concentrations of 29 cytokines from 38 patients were analyzed. Seventeen of these patients were diagnosed with engraftment syndrome using the Spitzer criteria. Patients who developed ES were shown to have significantly elevated levels of IL-1 receptor antagonist (IL-1Ra) in the apheresis product as compared to patients that did not develop ES (31,033 vs. 6015 pg/ml; p=0.028). IL-1Ra levels were not significantly different at other time points. IL-1Ra competes with IL-1α and IL-1β for binding to the IL-1 receptor thus acting as an antagonist to this proinflammatory cytokine. The gene encoding IL-1Ra has a tandem repeat sequence resulting in polymorphic alleles in the population with varying number of repeats. The allele containing 2 repeats, IL1RN*2, has been associated with various inflammatory diseases including Sjogren's syndrome, ulcerative colitis, Crohn disease, psoriasis, multiple sclerosis, and SLE. We performed PCR on the DNA isolated from the PBMCs of these patients to determine if patients with elevated IL-1Ra possessed the IL1RN*2 allele. Results did not find any correlation between IL-1RN*2 allele and elevated IL-1Ra levels in the apheresis samples. In addition, levels of the chemokine IFN-gamma-induced protein 10 (IP-10/CXCL10) were found to be significantly higher in patients diagnosed with ES at both the day 12 post-transplant (1089 vs. 689 pg/ml; p=0.022) and 2-4 month post-transplant time points (1768 vs. 922 pg/ml; p Disclosures Siegel: Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria. Biran:Takeda: Consultancy, Speakers Bureau; Merck: Research Funding; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; BMS: Research Funding. Vesole:Amgen: Speakers Bureau; Takeda: Speakers Bureau. Feldman:Janssen: Speakers Bureau; Pharmacyclics: Speakers Bureau; Celgene: Speakers Bureau; Johnson and Johnson: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; KITE: Speakers Bureau; Portola: Research Funding. Skarbnik:Novartis: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Introduction: Venetoclax (Ven), an oral BCL2 inhibitor, is approved for the treatment (tx) of relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). Ven is generally well tolerated, and side effects observed in clinical trials have been consistent with other CLL tx. Clinical trials using the approved dose escalation schedule report negligible rates of clinical tumor lysis syndrome (TLS). We aimed to understand rates of select adverse events (AEs) including cytopenias, infections, and TLS in CLL patients (pts) treated with Ven in community and academic settings. To do so, we examined 297 pts with CLL who received Ven, either alone or paired, in this multicenter, international study. Methods: We conducted a retrospective cohort study of Ven treated pts with CLL across at 15 academic (n=169) and 51 community (n=128) centers outside of the clinical trial setting. This study represents a collaboration between US centers, CLL Collaborative Study of Real World Evidence (CORE), and UK CLL Forum. Demographics, baseline disease characteristics, Ven dosing, TLS risk (per FDA Ven label) and prophylaxis, and AEs were collected. Lab vs. clinical TLS was defined by Howard criteria. PFS was estimated by Kaplan Meier methodology. All comparisons were descriptive. Results: Of the 297 pts examined, median age at Ven initiation was 67 (range 37-91). The group was 69% male, 96% had R/R CLL, and 45% had del17p. Baseline characteristics stratified by practice setting are included in Table 1. 80% received Ven as monotherapy while 20% received it paired with another agent (anti-CD20 mAb (75%), ibrutinib (8.5%), other (16.5%)). All pts were treated outside of clinical trials. During dose escalation, 81% achieved a 400 mg dose and 65% maintained 400 mg following escalation (cyp3A4 use unknown). TLS risk was low in 40%, intermediate (int) in 32%, and high risk in 28%. CT scan prior to Ven initiation was performed in 62%. At least one hospitalization occurred for 56% of low, 80% of int, and 88% of high risk pts (63% of the total cohort). Table 1 describes the distribution of TLS risk and frequency of hospitalizations in academic, community centers. TLS prophylactic measures were available for a subset of pts. Allopurinol was used for 91% (n=68/75) of low, 93% (n=52/56) of int, and 94% (n=29/31) of pts at high risk for TLS. Rasburicase was used for 27% (n=28/102) of low, 42% (n=34/81) of int, and 72% (n=57/79) of high risk pts. Normal saline was used in 85% (n=62/73) of low, 88% (n=49/56) of int, and 97% (n=30/31) of high risk pts. TLS occurred in 8.4% of pts (n=25/297). Three lab and 2 clinical events occurred in low risk pts, 7 lab and 3 clinical events in int risk pts, and 7 lab and 3 clinical events in high risk pts. Of pts with TLS, 1 has discontinued Ven. Of pts with clinical TLS, all were hospitalized, received allopurinol and normal saline, and 28% received rasburicase. 72% with TLS had creatinine clearance Select AEs were neutropenia (ANC7 stools/day) 6.9%. For the subset who received Ven paired, AEs were not increased: 35% neutropenia, 29% thrombocytopenia, 22% infection, 6.3% neutropenic fever, and 6.4% diarrhea. TLS was observed in 3.4% of pts who received Ven paired vs. 9.3% who received Ven monotherapy. 29% pts required ≥1 dose reduction and 32% had ≥1 dose interruption. Median length of dose interruption was 7 days (range 1 - 132). 22 pts (7.4%) discontinued Ven due to an AE. PFS was similar in pts with ≥1 dose interruption vs. 0, pts who required dose interruption ≥8 days vs. Conclusions: Ven was well tolerated in this cohort; AE rates were similar to those reported in clinical trials. Both academic and community sites employed TLS prophylaxis consistent with FDA/EMA recommendations resulting in a small proportion of clinical TLS events ( Disclosures Fox: Sunesis: Consultancy; Celgene: Consultancy, Other: Travel support, Speakers Bureau; Roche: Consultancy, Other: Travel support, Research Funding, Speakers Bureau; Gilead: Consultancy, Other: Travel support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Other: Travel support, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Personal fees and non-financial support, Speakers Bureau. Eyre:Gilead: Consultancy, Other: travel support; Abbvie: Consultancy, Other: travel support; Roche: Consultancy; Janssen: Consultancy, Other: travel support; Celgene: Other: travel support. Allan:Verastem: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy; Genentech: Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees. Schuster:OncLive: Honoraria; Physician's Education Source, LLC: Honoraria; Dava Oncology: Consultancy, Honoraria; Genentech: Honoraria, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Nordic Nanovector: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Nabhan:Cardinal Health: Employment, Equity Ownership. Hill:Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Shah:Lentigen Technology: Research Funding; Miltenyi: Other: Travel funding, Research Funding; Juno Pharmaceuticals: Honoraria; Exelexis: Equity Ownership; Oncosec: Equity Ownership; Geron: Equity Ownership. Lamanna:Jannsen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Coombs:AROG: Other: Travel fees; H3 Biomedicine: Honoraria; Abbvie: Consultancy; DAVA Oncology: Honoraria; Incyte: Other: Travel fees. Barr:AbbVie, Gilead: Consultancy. Skarbnik:Gilead Sciences: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Shadman:Pharmacyclics: Research Funding; Acerta Pharma: Research Funding; AstraZeneca: Consultancy; Genentech: Consultancy; Celgene: Research Funding; Verastem: Consultancy; Gilead Sciences: Research Funding; TG Therapeutics: Research Funding; AbbVie: Consultancy; Genentech: Research Funding; Mustang Biopharma: Research Funding; Beigene: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy. Ujjani:AbbVie: Consultancy, Speakers Bureau. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Jacobs:Genentech: Honoraria. Schuh:Giles, Roche, Janssen, AbbVie: Honoraria. Brander:Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria. Mato:Pharmacyclics: Consultancy, Honoraria, Research Funding; TG Therapeutics: Research Funding; Regeneron: Research Funding; Sunesis: Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Acerta: Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy; Celgene: Consultancy; Prime Oncology: Speakers Bureau.

Background: A regimen of escalating doses of thalidomide, in combination with bortezomib and high dose melphalan (Mel/Vel/Thal) was evaluated as a conditioning regimen for autologous stem cell transplantation (ASCT) in patients (pts) with multiple myeloma (MM) in a phase I/II study. Methods: Patients received Mel/Vel/Thal as a second of tandem ASCT if they achieved Results: Twenty-nine pts were enrolled: 9 in the phase 1 dose-escalation phase and an additional 20 pts in phase 2. In the phase I portion, all pts experienced somnolence, with grade 3 occurring in 1 pt at the 800 mg/day dose. Subsequently, Dex 40 mg was given with first dose of Thal at the 1000 mg level with decreased severity of somnolence. No dose limiting toxicities defined as ≥ grade 4 non-hematological SAEs occurred in the phase I portion, allowing full dose escalation with 9 pts enrolled. The maximum tolerated dose for Thal was not reached and the 1000 mg dose was chosen for the phase 2 dose expansion. No regimen related mortality occurred in either phase I or phase II portion of the study. All SAEs except lethargy and dizziness occurred after ASCT and were not attributed to Thal. The most common grade 1 and 2 non-hematologic toxicities included nausea (65.5%), mucositis (51.7%), diarrhea (48.3%), somnolence (48.3%), lethargy (27.6%), and vomiting (17.2%). The most common grade 3 non-hematologic adverse events (AEs) were neutropenic fever (58.6%), mucositis (6.9%), and somnolence (13.8%), which increased risk of falls. SAEs included somnolence (13.8%), tumor lysis syndrome (3.4%), and engraftment syndrome (3.4%). All transplant-related SAEs resolved by day +28 after ASCT. All pts achieved prompt hematological recovery with the median time to ANC >500/uL 10 days (range, 8-14 days), and platelet >20,000 12 days (range 9-26 days). All pts received at least one ASCT prior to enrolling on the study. Seventeen pts (59%) had interim salvage chemotherapy between their upfront and Mel/Vel/Thal ASCT (i.e. received a salvage ASCT), with median time from first to salvage ASCT 29 months. The remaining 12 (41%) went directly from an upfront ASCT Mel-based ASCT to the Mel/Vel/Thal ASCT (tandem ASCT) within 6 months of the first ASCT. Twenty-seven (93%) were Durie-Salmon stage III, and 13 (44%) had >2 prior lines of therapy. Of those who had Mel/Vel/Thal as a salvage ASCT, 70% had ≥3 prior lines of therapy. The overall response rate (ORR) was 69% with 38% complete remission. ORR for Mel/Vel/Thal compared to upfront Mel ASCT was 69% versus 62% with 11 patients achieving CR with Mel/Vel/Thal compared to 5 patients with Mel alone (Figure 1). Ten of 27 evaluable patients (37%) had an upgrade in response in the Mel/Vel/Thal salvage ASCT compared to their upfront ASCT: 2 pts (7%) went from PD to PR, 1 (4%) from SD to CR, 1 (4%) from PR to VGPR; 3 (11%) from PR to CR and 2 (7%) from VGPR to CR. Median PFS and OS were 9.3 and 65.4 months, respectively, with a median follow-up of 17.8 months. Of those who underwent tandem Mel followed by Mel/Vel/Thal ASCT the median PFS was 14.9 months with a median OS not yet reached at time of analysis. For the 17 patients who received a salvage Mel/Vel/Thal ASCT, median PFS from their upfront ASCT was 11.9 months, compared to 9.1 months with the salvage Mel/Vel/Thal ASCT. Conclusions: High-dose Thal up to 1000 mg daily for 5 days can be safely combined with Vel and dose-intense Mel as an ASCT conditioning regimen with acceptable toxicities. Confirmation of potential synergistic effects of this combination regimen will require an appropriately designed phase III study. Figure 1 Figure 1. Disclosures Biran: BMS: Research Funding; Merck: Research Funding; Takeda: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Skarbnik:Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau. Siegel:Novartis: Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Background: TA-TMA is a life-threatening complication of hematopoietic cell transplantation (HCT), usually manifested as a combination of non-immune mediated hemolytic anemia, thrombocytopenia and end-organ dysfunction (renal, neurologic and/or hypertension). Reported mortality rates following TA-TMA are high (50-75%; Gavriilaki et al, Bone Marrow Transplantation 2017). It is more commonly associated with allogeneic HCT, however, may infrequently occur with autologous HCT. Traditionally, treatment for TA-TMA consisted in removing possible offending agents (calcineurin inhibitors, sirolimus) and/or instituting total plasma exchange (PLEX). These approaches have not resulted in significant improvement in the natural history of TA-TMA, with complete resolution in 12-20% of pts (Mulay et al, J Clin Apher 2015). Recent evidence of alternate complement pathway activation has been implicated in the pathophysiology of TA-TMA (Jodele et al, Blood 2013). Eculizumab (ECU) is an anti-C5 monoclonal antibody, approved for treatment of PNH and aHUS, which has been used anecdotally as treatment for TA-TMA. Most reports consist of pediatric patients. In this analysis, we evaluated consecutive cases of adult recipients of HCT who developed TA-TMA and have received ECU therapy at our institution. Methods: We reviewed electronic records of consecutive patients who presented with a diagnosis of TA-TMA (non-immune hemolytic anemia plus worsening thrombocytopenia and end-organ dysfunction) and were treated with ECU between 2015 and 2017 at our institution. Univariate and bivariate statistics were calculated for the sample; Fisher's exact tests and Wilcoxon rank sum tests were utilized to test for differences across groups. Results: Table 1 shows the baseline characteristics of these pts. A total of 15 pts were included in the analysis; 2/3 were female and the median age was 62. ECU was given according to the usual schedule for aHUS (900 mg IV weekly x 4, 1200 mg every other week starting on week 5). Median time from TA-TMA diagnosis to initiation of ECU was 2 days. All patients received prophylaxis for Neisseria meningitides with ciprofloxacin and antifungal prophylaxis at initiation of ECU. Three (20%) pts received PLEX prior to ECU. Seven (47%) patients were receiving tacrolimus at diagnosis, however, levels were not within toxic range (3.7-7.9 ng/mL). Median time post-HCT for development of TA-TMA was 135 days. Median LDH, hemoglobin, platelet count and creatinine at TA-TMA diagnosis were 1724 U/L, 7.3 g/dL, 33,000/mcL and 1.7 mg/dL, respectively. Ten (66.6%) patients had acute kidney injury and 7 (46.6%) pts had neurologic manifestations. Eight (53.3%) pts had evidence of GVHD concurrent with TA-TMA diagnosis. Ten (63.3%) pts developed systemic infections during their TA-TMA treatment. No pts developed meningitis or fungal infections. Median follow-up was 4.5 months after initiation of ECU. Eight (53.3%) patients had complete resolution of TA-TMA (i.e. resolution of hemolytic anemia, thrombocytopenia and end-organ damage), 4 of these 8 pts were recipients of autologous HCT. Median time to resolution was 98 days and median cumulative ECU dose was 10,200 mg (range 4800-36400mg). An additional 2 pts (13%) presented clinical improvement without complete resolution of TA-TMA. Mortality secondary to TA-TMA or its complications was 33%. Median time to death was 31 days. The most common cause of mortality were infectious complications. Median survival for the entire cohort was 130 days (range 6-833 days, Figure). LDH >1300 U/L; more than one organ involvement, allogeneic HCT, use of tacrolimus and early ( Conclusion: To our knowledge, this is the largest reported series of adult pts with TA-TMA who were treated with ECU. Treatment with ECU for TA-TMA is associated with higher rates of resolution and lower rates of cause-specific mortality than what has been previously reported with other approaches. We hypothesize that higher cumulative doses of ECU are warranted to achieve resolution of TA-TMA. A prospective study utilizing a more intensive schedule of ECU infusions is required to confirm such hypothesis. Based on our analysis, we conclude that ECU is an appropriate - and potentially better - option in the treatment of TA-TMA. Disclosures Skarbnik: Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau.

Background: Despite advances in novel myeloma treatments and autologous hematopoietic stem cell transplantation (ASCT), allogeneic HSCT (alloSCT) remains the only curative option for patients (pts) with multiple myeloma (MM). Questions remain as to the timing of alloSCT, toxicity risks and optimal conditioning regimen. The addition of bortezomib (Vel) to fludarabine (Flu) and melphalan (Mel) for conditioning prior to alloSCT is based on the demonstrated safety of Vel in combination with melphalan prior to ASCT, the synergistic effect of Vel with Mel, and the ability of Vel to selectively eliminate allo-reactive T-cells. Methods: We present a prospective Phase II study using Flu/Mel/Vel (FMV) as a conditioning regimen for alloSCT. The primary endpoint is overall survival (OS), and secondary endpoints include progression free survival (PFS), incidence of graft-versus-host disease (GVHD) and transplant related mortality (TRM). For related donors, the conditioning regimen was Flu 30 mg/m2 days -5, -4, -3, -2, Vel 1.6 mg/m2 days -4, -1, Mel 140 mg/m2 day -2. For unrelated donors, rabbit ATG 4 mg/kg was given in divided doses days -3, -2, -1. GVHD prophylaxis consisted of methotrexate and tacrolimus. We compared pts receiving FMV to historical controls of pts receiving FM at the same dose and schedule without Vel. We also compared pts receiving FMV to all pts with MM treated with alloSCT including all regimens and donor types. The response criteria from the IMWG and M-Smart criteria were used to determine response and risk, respectively. Chi-square tests of association and Wilcoxon rank sum tests were performed to test for differences across groups. OS/PFS probabilities were calculated using the Kaplan-Meier product limit estimator with log rank-tests. Multivariate Cox proportional hazard models examined factors associated with OS/PFS. Results: Of the 54 pts who received FMV, 35 (65%) were male and the median age was 56 years. Twenty-seven pts had an HLA matched sibling donor and 27 had an unrelated donor. At the time of alloSCT, 5 pts were in a CR, 27 in a VGPR, 13 in a PR, 9 had < PR. Twenty eight pts (52%) had high risk disease. Twenty-nine pts (53%) received alloSCT as salvage, defined as relapsed or refractory to ASCT, and 25 pts (46%) as consolidation after ASCT. OS was 42% at 10 years. While 32 pts developed aGVHD, only 2 had ≥ Grade 3. Of the 31 pts who developed cGVHD, 23 were graded as extensive. TRM was 5% at day 100, and 15% over 10 years. Pts in the control groups had similar baseline characteristics to the FMV group. The only significant difference was 47 pts (72%) who received FM were transplanted as salvage, and 18 (28%) as consolidation after ASCT (p=0.035). The total number of pts who did not receive FMV (non FMV) was 121, with 66 pts receiving FM. Compared to pts who received FMV, there was no difference in OS for pts who received FM or the non FMV group, 35% (p=0.55) and 48% (p=0.855) respectively. There was no difference in pts who developed aGVHD, however 9 pts (13%) had ≥ grade 3 aGVHD in the FM group (p=0.004) and 15 (12%) in the non FMV group (p=0.006). The cumulative incidence of cGVHD was similar with 51% for pts receiving FM and 60% for FMV pts (p=0.32). TRM was similar to pts who had received FMV; 18% for FM and 17% for non FMV. There were no differences between the 3 groups across disease risk, donor type, or disease status at the time of alloSCT. Multivariate analysis of the 3 groups, shows achieving a CR after alloSCT (p=0.0006) or having cGVHD (p=0.0004) predicts for improved OS, while severe aGVHD (p=0.0002) predicts for decreased OS. Discussion: While FMV was associated with a lower incidence of severe aGVHD, the addition of bortezomib to the FM backbone did not improve PFS or OS. Day 100 TRM was low for all regimens, and the addition of Vel did not impact overall TRM. For all 175 pts, those who achieve a CR after alloSCT had a significantly improved OS. This prompts the question of whether strategies should be employed post alloSCT to maximize response to a CR, and the role of achieving MRD negativity after alloSCT also needs to be elucidated. Figure Figure. Disclosures Siegel: BMS: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Biran:Amgen: Consultancy, Speakers Bureau; BMS: Research Funding; Merck: Research Funding; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Skarbnik:Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Introduction: Venetoclax (Ven) is approved for relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) as monotherapy (Ven mono) or in combination (Ven paired) with rituximab based on clinical trials with selected patients (pts) and limited ibrutinib exposure. Whether Ven paired is superior to Ven mono, patterns of care, and outcomes following Ven discontinuation are unknown. Further, better delineation of adverse events (AEs) when Ven is used outside of clinical trials is needed. To address these gaps, we conducted a multicenter, international study in partnership with CLL Collaborative Study of Real World Evidence (CORE) and UK CLL Study Forum examining the clinical experience of 348 Ven treated CLL pts, representing the largest series of Ven treated pts reported to date. Methods: We conducted a retrospective cohort analysis of CLL pts treated with Ven across 24 US and 42 UK academic and community centers. We examined demographics, baseline disease characteristics, dosing, AEs, TLS risk and outcomes, response rates, outcomes (overall survival (OS) and progression free survival (PFS)), and tx sequencing. TLS events were defined by Howard criteria. PFS and OS were estimated by the Kaplan Meier method. Comparisons of outcomes used the Log Rank test. Univariate and multivariate analyses were performed with COX regression. All other comparisons were descriptive. Results: Of these 348 CLL pts, 94% were R/R, median age 67 years (range:37-91), 69% male, 85% white, and 73% Rai stage ≥2. 19% received Ven on clinical trial. 79% had Ven mono; Ven was paired most commonly with anti-CD20 (n=51) and ibrutinib (n=10). Pts received a median of 3 tx (range 0-15) before Ven; 78% received ibrutinib, 29% received PI3Ki, 20% had ≥2 prior kinase inhibitors, and 68% had chemoimmunotherapy. Median time from most recent tx to Ven start was 1.1 months (range 0-62). Pre-Ven prognostic markers included 43% del17p, 34% TP53 mutated, 24% del11q, 38% complex karyotype (≥ 3 abnormalities), and 84% IGHV unmutated (Table 1). TLS risk was low in 38%, intermediate in 34% and high in 28%. During ramp up, TLS was observed in 10% (22 lab, 9 clinical TLS events, 3 missing data). Following dose escalation, 70% achieved a stable Ven dose of 400 mg, 33% required ≥ 1 dose interruption and 27% required ≥ 1 dose reduction. AEs included grade 3 neutropenia 39%, grade 3 thrombocytopenia 29%, infections 25%, grade ≥ 2 diarrhea 7.8%, and neutropenic fever 7.7%. AEs were similar whether treated on or off clinical trial. The ORR to Ven mono, Ven paired was 81% (34% CR), 86% (29% CR). With a median follow-up of 14.2 months, median PFS and OS were not reached (12 month PFS 74%, OS 82%). Figure 1 depicts PFS stratified by Ven mono vs. paired, clinical trial vs. clinical practice, del17p status, and complex karyotype. Pts who discontinued Ven due to AEs had better OS compared with those who discontinued due to progression or Richter Transformation (RT) (Median OS 47 vs. 15.1 vs. 8.6 months, respectively). In multivariate analyses, complex karyotype was the only independent predictor of PFS (HR 2.8, p Conclusions: In this heavily pretreated, poor risk group, Ven showed favorable outcomes with comparable toxicity and efficacy on or off clinical trial. Similar outcomes were observed for Ven mono and Ven paired; longer follow up is needed from studies of Ven paired to understand depth and durability of response. Complex karyotype independently predicted inferior PFS and OS. Without complex karyotype, del(17p), multiple lines of prior tx, and prior ibrutinib tx were independent predictors of inferior outcomes. Outcomes of retreatment with KI in Ven-failure previously treated with KI were poor. Data on sequencing cellular therapies post Ven is forthcoming. Disclosures Mato: AbbVie: Consultancy, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; Regeneron: Research Funding; AstraZeneca: Consultancy; Medscape: Honoraria; TG Therapeutics: Consultancy, Research Funding; Acerta: Research Funding; Prime Oncology: Honoraria; Portola: Research Funding; Celgene: Consultancy; Johnson & Johnson: Consultancy. Eyre:Abbvie: Consultancy, Other: travel support; Janssen: Consultancy, Other: travel support; Roche: Consultancy; Gilead: Consultancy, Other: travel support; Celgene: Other: travel support. Nabhan:Cardinal Health: Employment, Equity Ownership. Lamanna:Acerta: Research Funding; TG Therapeutics: Research Funding; Jannsen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hill:Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Brander:Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Teva: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Barr:AbbVie, Gilead: Consultancy. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Shah:Geron: Equity Ownership; Lentigen Technology: Research Funding; Exelexis: Equity Ownership; Oncosec: Equity Ownership; Miltenyi: Other: Travel funding, Research Funding; Juno Pharmaceuticals: Honoraria. Allan:AbbVie: Membership on an entity's Board of Directors or advisory committees; Verastem: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees. Kennard:AbbVie, Gilead, Verastem: Consultancy. Schuster:Gilead: Membership on an entity's Board of Directors or advisory committees; Nordic Nanovector: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Honoraria, Research Funding; Physician's Education Source, LLC: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Research Funding; Dava Oncology: Consultancy, Honoraria; OncLive: Honoraria; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Skarbnik:Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau. Coombs:AROG: Other: Travel fees; Abbvie: Consultancy; Incyte: Other: Travel fees; DAVA Oncology: Honoraria; H3 Biomedicine: Honoraria. Ujjani:AbbVie: Consultancy, Speakers Bureau. Jacobs:Genentech: Honoraria. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Schuh:Giles, Roche, Janssen, AbbVie: Honoraria. Shadman:Celgene: Research Funding; Gilead Sciences: Research Funding; Mustang Biopharma: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Consultancy; Pharmacyclics: Research Funding; Genentech: Research Funding; Genentech: Consultancy; Acerta Pharma: Research Funding; Beigene: Research Funding; Verastem: Consultancy; Qilu Puget Sound Biotherapeutics: Consultancy; AbbVie: Consultancy. Fox:Abbvie: Consultancy, Other: travel support, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: travel support, Speakers Bureau; Gilead: Consultancy, Other: travel support, Research Funding, Speakers Bureau; Roche: Consultancy, Other: travel support, Research Funding, Speakers Bureau; Celgene: Consultancy, Other: travel support, Speakers Bureau; Sunesis: Consultancy.

Background: Autologous stem cell transplantation (ASCT) is increasingly offered to older patients with multiple myeloma (MM) based on clinical trials demonstrating improved outcome. Inherently, successful mobilization and collection of peripheral blood stem cells (PBSC) is necessary for ASCT. A direct comparison of the efficacy of mobilization between elderly and younger patients has not been reported. Retrospective studies demonstrated that older patients had lower CD34+ cell yield and a higher incidence of mobilization failure (Lee et al 2014, Muchtar et al 2016). In this retrospective study, we compared two age groups (>/=70 years and Methods: MM patients who received a single ASCT at our institution between 2005 and 2016 were included. More than 95% of patients received either cyclophosphamide-based chemotherapy with GCSF (CY-GCSF) or plerixafor with GCSF (Pleri-GCSF) and were included in the analysis. We identified 111 patients aged >/= 70 years and 315 patients Progression-free survival (PFS) and overall survival (OS) were compared using Cox proportional hazard model with the above-mentioned covariates. All analyses were done using SAS 9.4. Results: Patient characteristics and CD34+ cell yield by age group are summarized in Table 1. The majority of patients in both groups underwent mobilization within one year of diagnosis. Older patients were less likely to receive CY-GCSF and more likely to receive Pleri-GCSF compared to younger patients (p0.05 for all). The two groups had similar number of apheresis sessions regardless of mobilization regimen. When receiving Pleri-GCSF, the two age groups had similar CD34+ yield per apheresis (4.4x10e6 /kg and 3.9x10e6 /kg for age>/=70 and age In the multivariate analysis including all patients, time from diagnosis to mobilization, disease stage and disease status at mobilization were not associated with CD34+ yield per session or total CD34+ yield. Neither age nor mobilization regimen was associated with PFS or OS, after adjusting for disease stage and disease status at ASCT (Table 2, Figure 1, Figure 2). Conclusions: CD34+ yield was comparable between younger patients and older patients receiving plerixafor + GCSF. In contrast, the CD34+ yield was lower in the older patients receiving cyclophosphamide + GCSF. The cause of the difference is not clear and warrants further study. The PFS and OS were comparable between the two groups after ASCT. The choice of mobilization regimen did not affect survival. We have previously advocated cyclophosphamide mobilization in most patients because of the higher CD34+ yield and lower cost compared to plerixafor + GCSF (Panchal et al., ASH 2017). However this study showed that the CD34+ yield was not significantly different for patients aged 70 years or older in response to the different mobilization regimens. It is reasonable to consider plerixafor + GCSF in the elderly when chemotherapy toxicity is of concern. Disclosures Siegel: Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau. Biran:Amgen: Consultancy, Speakers Bureau; Merck: Research Funding; Celgene: Consultancy, Honoraria, Speakers Bureau; BMS: Research Funding; Takeda: Consultancy, Speakers Bureau. Skarbnik:Gilead Sciences: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

6577Background: Differences in outcomes have been reported in CLL pts receiving chemo±immunotherapy with non-Caucasians and males having inferior outcomes. Less is known if such disparities exist f...

8025Background: Autologous stem cell transplantation (ASCT) has improved the outcome of patients with Multiple Myeloma (MM) substantially and is now the standard of care. Patients over the age of 7...

Mantle cell lymphoma accounts for 6% of all non-Hodgkin lymphomas. It is a biologically and clinically heterogeneous disease and treatment may be difficult, since most patients present at an older age, being unable to undergo intensive chemotherapy. Lenalidomide is an approved medication for relapsed mantle cell lymphoma in patients who received at least two lines of therapy, including bortezomib. New insights into the mechanisms of action of lenalidomide provided ground for novel combinations that may be more tolerable, while still efficient, for this patient population. In this review, we evaluate the current paradigm for lenalidomide in mantle cell lymphoma.

e19030 Background: The peripheral blood absolute lymphocyte-to-monocyte ratio (ALC/AMC) is prognostic of overall survival (OS) in Hodgkin Lymphoma, Diffuse Large B-cell Lymphoma, and several solid tumors. Lymphocyte and monocytes have been suggested to be surrogate biomarkers of immune homeostasis and tumor microenvironment, respectively. We sought to determine if the post-induction therapy ALC/AMC is prognostic in mantle cell lymphoma. Methods: A retrospective review was conducted of 96 consecutive mantle cell lymphoma patients (pts) with available data treated at the John Theurer Cancer Center (n=77) and 4 Regional Cancer Care Associate practices (n=19) by 24 physicians between Aug 2005 and Dec 2015 (90% cases after 2009). Cases were identified via the COTA database which extracts and organizes relevant data from the electronic health records. Peripheral blood counts (to calculate the ALC/AMC) were determined approximately 30 days following completion of initial therapy or immediately prior to stem cell mobilization in those pts undergoing first line transplant. All analyses were performed using the R statistical language. Results: 67 pts had ALC/AMC less than 2 and 29 pts had ALC/AMC greater than or equal to 2. The cohorts (2) had similar median ages (64 vs 68; p=0.18), ethnicities (p=0.38), stage distributions (including 87% vs 79% stage IV disease; p=0.51), elevated beta-2-microglobulin (p=1), elevated LDH (p=1) and MIPI scores (including 19% vs 41% high risk; p=0.13). ALC/AMC was 2, following induction therapy, is associated with improved overall survival in MCL. Novel maintenance programs, including targeting the microenvironment or immune response, might be appropriate among pts with low ratios.