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We performed a phase 1 clinical trial to evaluate outcomes in patients receiving donor-derived CD19-specific chimeric antigen receptor (CAR) T cells for B-cell malignancy that relapsed or persisted after matched related allogeneic hemopoietic stem cell transplant. To overcome the cost and transgene-capacity limitations of traditional viral vectors, CAR T cells were produced using the piggyBac transposon system of genetic modification. Following CAR T-cell infusion, 1 patient developed a gradually enlarging retroperitoneal tumor due to a CAR-expressing CD4(+) T-cell lymphoma. Screening of other patients led to the detection, in an asymptomatic patient, of a second CAR T-cell tumor in thoracic para-aortic lymph nodes. Analysis of the first lymphoma showed a high transgene copy number, but no insertion into typical oncogenes. There were also structural changes such as altered genomic copy number and point mutations unrelated to the insertion sites. Transcriptome analysis showed transgene promoter–driven upregulation of transcription of surrounding regions despite insulator sequences surrounding the transgene. However, marked global changes in transcription predominantly correlated with gene copy number rather than insertion sites. In both patients, the CAR T-cell–derived lymphoma progressed and 1 patient died. We describe the first 2 cases of malignant lymphoma derived from CAR gene–modified T cells. Although CAR T cells have an enviable record of safety to date, our results emphasize the need for caution and regular follow-up of CAR T recipients, especially when novel methods of gene transfer are used to create genetically modified immune therapies. This trial was registered at www.anzctr.org.au as ACTRN12617001579381.

The leukocyte NADPH oxidase 2 (NOX2) plays a key role in pathogen killing and immunoregulation. Genetic defects in NOX2 result in chronic granulomatous disease (CGD), associated with microbial infections and inflammatory disorders, often involving the lung. Alveolar macrophages (AMs) are the predominant immune cell in the airways at steady state, and limiting their activation is important, given the constant exposure to inhaled materials, yet the importance of NOX2 in this process is not well understood. In this study, we showed a previously undescribed role for NOX2 in maintaining lung homeostasis by suppressing AM activation, in CGD mice or mice with selective loss of NOX2 preferentially in macrophages. AMs lacking NOX2 had increased cytokine responses to Toll-like receptor-2 (TLR2) and TLR4 stimulation ex vivo. Moreover, between 4 and 12 week of age, mice with global NOX2 deletion developed an activated CD11bhigh subset of AMs with epigenetic and transcriptional profiles reflecting immune activation compared with WT AMs. The presence of CD11bhigh AMs in CGD mice correlated with an increased number of alveolar neutrophils and proinflammatory cytokines at steady state and increased lung inflammation after insults. Moreover, deletion of NOX2 preferentially in macrophages was sufficient for mice to develop an activated CD11bhigh AM subset and accompanying proinflammatory sequelae. In addition, we showed that the altered resident macrophage transcriptional profile in the absence of NOX2 is tissue specific, as those changes were not seen in resident peritoneal macrophages. Thus, these data demonstrate that the absence of NOX2 in alveolar macrophages leads to their proinflammatory remodeling and dysregulates alveolar homeostasis.

Hematopoietic cell transplantation from HLA-haploidentical related donors is increasingly used to treat hematologic cancers; however, characteristics of the optimal haploidentical donor have not been established. We studied the role of donor HLA mismatching in graft-versus-host disease (GVHD), disease recurrence, and survival after haploidentical donor transplantation with posttransplantation cyclophosphamide (PTCy) for 1434 acute leukemia or myelodysplastic syndrome patients reported to the Center for International Blood and Marrow Transplant Research. The impact of mismatching in the graft-versus-host vector for HLA-A, -B, -C, -DRB1, and -DQB1 alleles, the HLA-B leader, and HLA-DPB1 T-cell epitope (TCE) were studied using multivariable regression methods. Outcome was associated with HLA (mis)matches at individual loci rather than the total number of HLA mismatches. HLA-DRB1 mismatches were associated with lower risk of disease recurrence. HLA-DRB1 mismatching with HLA-DQB1 matching correlated with improved disease-free survival. HLA-B leader matching and HLA-DPB1 TCE-nonpermissive mismatching were each associated with improved overall survival. HLA-C matching lowered chronic GVHD risk, and the level of HLA-C expression correlated with transplant-related mortality. Matching status at the HLA-B leader and HLA-DRB1, -DQB1, and -DPB1 predicted disease-free survival, as did patient and donor cytomegalovirus serostatus, patient age, and comorbidity index. A web-based tool was developed to facilitate selection of the best haploidentical-related donor by calculating disease-free survival based on these characteristics. In conclusion, HLA factors influence the success of haploidentical transplantation with PTCy. HLA-DRB1 and -DPB1 mismatching and HLA-C, -B leader, and -DQB1 matching are favorable. Consideration of HLA factors may help to optimize the selection of haploidentical related donors.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive neoplasm immunophenotypically resembling regulatory T cells, associated with human T-cell leukemia virus type-1. Here, we performed whole-genome sequencing (WGS) of 150 ATL cases to reveal the overarching landscape of genetic alterations in ATL. We discovered frequent (33%) loss-of-function alterations preferentially targeting the CIC long isoform, which were overlooked by previous exome-centric studies of various cancer types. Long but not short isoform–specific inactivation of Cic selectively increased CD4(+)CD25(+)Foxp3(+) T cells in vivo. We also found recurrent (13%) 3′-truncations of REL, which induce transcriptional upregulation and generate gain-of-function proteins. More importantly, REL truncations are also common in diffuse large B-cell lymphoma, especially in germinal center B-cell–like subtype (12%). In the non-coding genome, we identified recurrent mutations in regulatory elements, particularly splice sites, of several driver genes. In addition, we characterized the different mutational processes operative in clustered hypermutation sites within and outside immunoglobulin/T-cell receptor genes and identified the mutational enrichment at the binding sites of host and viral transcription factors, suggesting their activities in ATL. By combining the analyses for coding and noncoding mutations, structural variations, and copy number alterations, we discovered 56 recurrently altered driver genes, including 11 novel ones. Finally, ATL cases were classified into 2 molecular groups with distinct clinical and genetic characteristics based on the driver alteration profile. Our findings not only help to improve diagnostic and therapeutic strategies in ATL, but also provide insights into T-cell biology and have implications for genome-wide cancer driver discovery.

Introduction The management of Waldenström's Macroglobulinemia (WM), a rare and incurable B-cell non-Hodgkin lymphoma, has evolved in recent years. Treatment options are increasing including more modern targeted therapies. Therefore there are currently several effective treatment options available for WM. There is no consensus on a preferred treatment. Widely used treatment options include rituximab combined with chemotherapy, proteasome inhibitors, and the oral BTK inhibitor ibrutinib. These treatments have varying properties in terms of efficacy, toxicity profile, duration (fixed-duration vs long-term maintenance), administration (oral vs intravenous/subcutaneous (IV/SC)), and type of agent (chemotherapy vs targeted therapy). A better understanding of patients' treatment preferences could aid physicians in developing an individualized treatment plan. Also, a better insight in patients' treatment views could help direct future clinical studies in WM. However, treatment preferences of WM patients have not been investigated. We aimed to evaluate treatment preferences of WM patients by means of a discrete choice experiment (DCE) and to assess the importance of different attributes describing the currently available treatment regimens. Methods A mixed-method approach, consisting of a literature review, qualitative interviews and expert discussions was utilized for identification and selection of attributes/levels. A DCE questionnaire was developed in Dutch and included 5 treatment-related attributes: 5-year progression-free survival (PFS), frequency/route of administration(IV/SC or oral)/setting (clinic or home) of treatment, adverse events (nausea & vomiting and fatigue, neuropathy and atrial fibrillation), risk of future secondary malignancies (low vs high), and type of treatment agent (chemotherapy or targeted therapy). Each respondent was presented with 16 choice cards and was asked to choose between two hypothetical but realistic treatment options (see Figure 1 for an example). A pilot DCE study was carried out in 5 patients to evaluate feasibility. Data were collected via a nationwide online questionnaire via the patient organizations' website and via paper-based questionnaires sent to the participants known at the outpatient clinic. An orthogonal design was used to construct the choice tasks and a mixed logit panel data model was used to assess patients' preferences and trade-offs between attributes/levels. Results A total of 330 online questionnaires and 17 paper-based questionnaires were returned. After excluding incomplete survey data, 214 (65%) questionnaires were included for data analysis, respondents characteristics are presented in Table 1. The 5-year PFS followed by the risk of secondary malignancies were the most important attributes for making treatment decisions. The probability of choosing a treatment option increased with 26% and 22% if the 5-year PFS increased from 50% to 70% and if the chance of future secondary malignancies was decreased from "high risk" to "low risk", respectively. Of the adverse events, patients disliked being at risk for neuropathy the most more than nausea, vomiting and extreme fatigue. Patients were willing to give up 7,2% treatment efficacy to avoid risk of neuropathy. The probability of choosing a treatment option increased with 8% for a fixed-duration treatment with IV/SC administration at the hospital compared to an ongoing daily oral regimen at home (Table 2). Socio-demographic characteristics such as age, gender and treatment status did not significantly influence patients' preferences with the exception of educational status. Lower 5-year PFS was more acceptable for patients with higher education (P Conclusion These are the first data on WM patients' preferences on treatment characteristics. We found that Dutch WM patients find efficacy (high 5-year PFS rate) the most important attribute, followed by a low risk of future secondary malignancies. Neuropathy was the adverse event they most wanted to avoid. They preferred a fixed-duration IV/SC treatment over an ongoing oral regimen. These data can be used in discussions with individual patients about their treatment preference, and help direct future clinical trials that optimally connect to WM patients' preferences. Figure 1 Figure 1. Disclosures Minnema: Cilag: Consultancy; Janssen: Consultancy; Celgene: Other: Travel expenses; Alnylam: Consultancy; BMS: Consultancy; Kite/Gilead: Consultancy. Kersten: Miltenyi Biotec: Consultancy, Honoraria, Other: Travel support; Roche: Consultancy, Honoraria, Other: Travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: Travel support; BMS/Celgene: Consultancy, Honoraria; Takeda: Research Funding; Celgene: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support, Research Funding. Vos: Celgene: Other: Travel reimbursement; Sanofi: Membership on an entity's Board of Directors or advisory committees.

The European LeukemiaNet (ELN) recently revised both the clinical (2022) and measurable residual disease (MRD) testing (2021) guidelines for acute myeloid leukemia (AML). Updated World Health Organization (WHO) and an International Consensus Classification (ICC) for myeloid neoplasms were also published in 2022. Together, these documents update the classification, risk stratification, prognostication, monitoring recommendations, and response assessment for patients with AML. Increased appreciation of the genetic drivers of AML over the past decade and our increasingly sophisticated understanding of AML biology have been translated into novel therapies and more complex clinical treatment guidelines. Somatic genetic abnormalities and germline predispositions now define and guide treatment and counseling for subtypes of this hematologic malignancy. In this paper, we discuss how we approach AML in daily clinical practice taking into consideration these recent updates in the context of new treatments and discoveries over the past decade.

Both BTKi and BCL2i are regarded as standards of care for frontline treatment of CLL. In this paper, I present the arguments for favoring BTKi as initial therapy. Venetoclax-based regimens have the advantage of being fixed in duration, but patients with select high-risk features may experience inferior PFS relative to those without high-risk features.

Patients with B-lineage acute lymphoblastic leukemia (ALL) are at high-risk for relapse after allogeneic hematopoietic cell transplantation (HCT). We conducted a single-center phase 2 study evaluating the feasibility of 4 cycles of blinatumomab administered every 3 months during the first year after HCT in an effort to mitigate relapse in high-risk ALL patients. Twenty-one of 23 enrolled patients received at least 1 cycle of blinatumomab and were included in the analysis. The median time from HCT to the first cycle of blinatumomab was 78 days (range, 44 to 105). Twelve patients (57%) completed all 4 treatment cycles. Neutropenia was the only grade 4 adverse event (19%). Rates of cytokine release (5% G1) and neurotoxicity (5% G2) were minimal. The cumulative incidence of acute graft-versus-host disease (GVHD) grades 2 to 4 and 3 to 4 were 33% and 5%, respectively; 2 cases of mild (10%) and 1 case of moderate (5%) chronic GVHD were noted. With a median follow-up of 14.3 months, the 1-year overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) rates were 85%, 71%, and 0%, respectively. In a matched analysis with a contemporary cohort of 57 patients, we found no significant difference between groups regarding blinatumomab’s efficacy. Correlative studies of baseline and posttreatment samples identified patients with specific T-cell profiles as “responders” or “nonresponders” to therapy. Responders had higher proportions of effector memory CD8 T-cell subsets. Nonresponders were T-cell deficient and expressed more inhibitory checkpoint molecules, including T-cell immunoglobulin and mucin domain 3 (TIM3). We found that blinatumomab postallogeneic HCT is feasible, and its benefit is dependent on the immune milieu at time of treatment. This paper is posted on ClinicalTrials.gov, study ID: NCT02807883.

Introduction Therapy-related leukemia or secondary leukemia are the terms that describe the occurrence of leukemias following exposure to hematotoxins and radiation to emphasize the difference from leukemia that arises de novo . Many leukemogenic agents have been described, including radiation, alkylating agents, among others . Certain host factors contribute to this predisposition, such as polymorphisms in drug-metabolizing enzymes and inherited cancer predisposition syndrome . These rising leukemias have no specific biologic features that set them apart from de novo malignancies . Therapy-related acute myeloid leukemia (t-AML) has extensive literature to support it. In contrast, therapy-related chronic myeloid leukemia (t-CML) possibly because it originates from a more potent premature progenitor cell . Radioactive iodine (RAI) with I 131 has an established role in managing differentiated thyroid carcinoma, namely papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma. However, concerns have been raised about its possible carcinogenic effects. Papers of t-CML following I 131 are increasingly reported, and thus this review is dedicated to highlighting it. Designs and methods All reports from the 1960s to date related to CML following RAI therapy were searched on Google Scholar and PubMed. Different search terms with Boolean function to search for the relevant articles. All articles were in English. Results We identified ten articles reporting 12 cases, as presented in table 1. We found that most of the reports were for men (8/12) under the age of 60 years (10/12), and the primary tumor was of PTC characteristics (5/12 were PTC, and 3/12 were mixed papillary-follicular carcinoma). The dose of I 131 ranged between 30 millicuries (mCi) to 850 mCi; the mean dose was 331 mCi. Also, t-CML developed within the first ten years (9/12), mainly between 4-7 years post-exposure. Discussion A few reports found a statistically significant increased risk of leukemia following RAI therapy; some suggested a relative risk of 2.5 for I 131 vs. no I 131 . Observed findings from these studies include a linear relationship between the cumulative dose of I 131 and the risk of leukemia, doses higher than 100 mCi were associated with a greater risk of developing secondary leukemia, and most of the leukemias developed within the initial ten years of exposure . The precise mechanism through which RAI provokes leukemia is largely unclear. Possibly, by inducing oxidative stress, reactive oxygen species production results in damage to the cellular membrane, DNA strand breakage, DNA base alterations, and eventually cancer in the instances of poor repair of damage . Many questions remain open. For example, most of the subjects had PTC histopathology in our review. Is there a relationship between PTC and the emergence of leukemia? This question is relevant because some reported that PTC has a mutation of the RET protooncogene, which has been linked to leukemia, prostate and breast cancers. Conclusion Although the risk of t-CML appears to be low based on current reports, it should not be disregarded. Further studies are needed to establish or refute a causal relationship. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Reports of "positive" results in early phase trials as presented at ASH presumably herald therapeutic advances, or at a minimum, a larger, potentially confirmatory, randomized trial. However, the predictive value of an ASH abstract reporting positive results in AML for subsequent clinical utility seems low (Estey 2006, ASH). Furthermore, not all results presented at ASH are published in peer-reviewed journals, and selectively publishing positive results leads to publication bias. Moreover, truly negative studies may be scientifically more rigorous and accurate than positive studies given the unequivocal findings. The extent of publication bias is unknown as is the frequency with which positive or negative abstracts lead to subsequent investigation in phase III and the reasons why positive phase II studies might not progress to phase III. We downloaded all 2013 - 2015 ASH abstracts (N = 17,251) and evaluated all abstracts reporting phase II clinical trials (N = 371) of novel drugs and therapeutic regimens presented at ASH in these years, covering investigational treatments of MM, CLL, AML, DLBCL, MDS, NHL, ALL, CML, MCL, SLL, other lymphomas and POEMS. We first scored abstracts "positive", "negative" or "inconclusive". Criteria for a positive abstract were words/phrases such as "encouraging", "promising", "could represent a novel therapeutic option" and "warrants investigation in a randomized trial". Negative abstracts included terms such as "does not support further research" and "demonstrates no clinical activity". The remainder were scored as inconclusive. Using this approach, we scored 296/371 (80%) abstracts as positive, 37/371 (10%) as negative, and 38/371 (10%) as inconclusive. 292/371 abstracts (79%) were published in peer-reviewed journals. The abstract conclusion (positive, negative or inconclusive) was not associated with publication in a peer-reviewed journal. Most frequently, studies were published in Blood (34/292 [11.6%]) and British Journal of Haematology (39/292 [13.4%]) . In Blood, 91% (31/34) of the studies were positive. British Journal of Haematology published significantly more negative studies than Blood (26%, Fisher Exact p = 0.02). Abstracts reporting studies with larger sample sizes tended to be published more often (p = 0.066). Differences exist between the abstract conclusion and later peer-reviewed publications. Of positive ASH abstracts, 6% changed to a negative conclusion in the peer-reviewed publication. Similarly, 6.5% of the initial negative abstract later reversed to a positive conclusion. 53% of positive abstracts did not lead to phase III studies, as registered on clinicaltrials.gov. Subsequently, regimens described in positive peer-reviewed publications did not proceed to phase III research in 48%. To explore why, we sent questionnaires to the first and/or last authors of positive studies not prompting phase III trials. 52% responded. Failure of positive phase II trials to proceed to phase III was due to the decision by the pharmaceutical company to halt clinical investigation (44%), lack of any intent to study the drug in phase III in the first place (40%), insufficient funding (35%), insufficient efficacy (despite the "positive" abstract; 33%) and safety concerns (4%) (Figure). Additional reasons for not proceeding to phase III were the availability of newer regimens, the rarity of the disease, or when regulatory approval had already been obtained after phase II. In conclusion, "positive" and "negative" ASH abstracts are published as full papers equally often, although the positive ones may be published more often in journals with higher "impact factors". More than half of the regimens presented in positive ASH abstracts remain unevaluated in randomized phase III trials. A separate problem is the likely tendency to disproportionately submit (and/or accept) positive, rather than negative, studies to ASH in the first place. We believe our findings raise issues in clinical research that may not be in the best interest of patients. This demands more consideration than it currently receives. Figure 1 Figure 1. Disclosures Ossenkoppele: Astellas: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Abbvie, AGIOS, BMS/Celgene Astellas,AMGEN, Gilead,Servier,JAZZ,Servier Novartis: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Gilead: Consultancy, Honoraria. Rowe: Biosight Inc.: Consultancy.

Background: Patients with advanced peripheral and cutaneous T-cell lymphomas (PTCL and CTCL) have an unfavorable prognosis . Primary refractoriness to traditional chemotherapy and relapse is common. Few FDA-approved "novel" single agents (SA) are available but their effectiveness as salvage agents relative to traditional multiagent cytotoxic chemotherapy (CC) regimens remains unknown. Therefore, we conducted a systematic meta-analysis to compare the response rates of approved and experimental single agents to conventional chemotherapy for patients with relapsed and refractory (R/R) PTCL and CTCL. Methods: This systematic review is reported in accordance with the PRISMA guidelines. Briefly a Harvard University Librarian (PB) systematically searched the publication libraries of: MEDLINE (through Ovid SP), Embase, Web of Science Core Collection, and Cochrane's Central Register for adult patients with R/R PTCL and CTCL enrolled in phase I, II, and III clinical trials of novel single and cytotoxic drugs. Agents determined as novel included antifolates, histone deacetylase inhibitors (HDACi), antibody-drug conjugates, therapeutic antibodies, hypomethylating agents, cereblon modulators, inhibitors of PI3K/AKT/mTOR, JAK/STAT, aurora kinase, farnesyl transferase and proteosome pathways, and CD4 CAR T- cells. Conventional chemotherapy agents included ifosfamide-, gemcitabine-, anthracycline-, and platinum-based treatments. Three researchers (NS, RS and LB) independently reviewed eligible studies and extracted data for baseline demographics, histological subtype, treatment characteristics including response rates, duration of response, overall and progression free survival, toxicity, and risk of bias assessment. Primary outcome was overall response rate (ORR), defined as the best reported partial response (PR) or better. Meta-analyses were conducted for ORR and the scale of logarithm of odd using the generic inverse variance method. The random effects model was used to pool the effect sizes for each study assuming a normal distribution of the random effects. Preplanned subgroup by therapy type and histological subtypes of lymphoma were treated as fixed effects and compared using Wald test. The degree of statistical heterogeneity was evaluated by inconsistency index (I2). Results: Our literature search identified 1873 articles, which after filtering for inclusion and exclusion criteria, ruling in only papers including T-cell lymphoma specific response, was narrowed to 128 studies for data extraction. Of these 128 studies, 35 were phase I trials, 70 phase II, 13 phase III, and 10 were combination. First, we divided all studies into upfront (n=33) versus R/R (n=100) based on timing of their treatments. We specifically focused on patients with R/R TCLs and subdivided those studies into the novel SA (n=84) and conventional chemotherapy (n=16) categories. The ORR for novel agents was lower at 37% (95% confidence interval [CI]: 34, 41) in comparison with 55% (95% CI: 40, 69) for standard chemotherapy agents (p=0.02). When stratified by histological subtype, patients with PTCL-NOS (n=751) had comparable ORR to novel agents (31%; 95% CI: 27, 35) and conventional chemotherapy (40%; 95% CI: 31,50; p=0.08). Similar results were seen with patients with AITL (n=296) who achieved equivocal ORR to single agents (45%; 95% CI: 38, 52) when contrasted with conventional chemotherapy (55%; 95% CI: 27, 80; p=0.52). Similar efficacy was seen for patients with CTCL (n=612) across SA (34%, 95% CI:29, 40) and CC (44%; 95% CI: 33, 56; p=0.11). Conclusions: Our meta-analysis highlights that for particular histological subtypes of PTCL such as PTCL-NOS and AITL, single agents are non-inferior to cytotoxic chemotherapy regimens in the R/R setting. These findings warrant serious consideration in the design and development of clinical trials for patients with R/R PTCL and the need for tailored treatments. Our meta-analysis also informs clinicians and patients about the benefits of single agents in comparison with standard chemotherapy while making clinical decisions for specified histologies. Disclosures Foss: Mallinckrodt: Honoraria; Kyowa: Honoraria; Kura: Honoraria; Seattle Genetics: Honoraria, Speakers Bureau; Acrotech: Honoraria, Speakers Bureau; Daiichi Sankyo: Honoraria. Jain: Trillium Therapeutics, Inc: Research Funding; Acro Biotech, Inc: Research Funding; Abcuro, Inc: Research Funding.

Introduction: Over the past 21 years, treatment options for hemophilia have evolved significantly. The objective of this study is to describe the trends observed in clinician prescribing practices for management of hemophilia A (HA) and B (HB) in the United States (US) via three surveys from 1999-2021. Methods: We administered surveys to members of the Hemostasis & Thrombosis Research Society (HTRS) via an in-person paper survey at its annual symposia in 1999 and 2015, and an online survey in 2021. The survey participants included physicians, physician assistants, and nurse practitioners who manage the care of hemophilia patients at hemophilia treatment centers in the US. The surveys collected information regarding: 1) characteristics of clinician practice, 2) prescribed clotting factor products and dosages used for routine bleeds or major life-threatening bleeding, total joint replacement, and port placement, 3) reasons for changing doses, 4) frequency of recommendation for prophylaxis and inhibitor treatment for associated factor and non-factor products, and 5) gene therapy. Results: Forty-one clinicians completed the survey in 1999 and 2021, 53 in 2015. The mean number of patients seen by respondents increased from 142 (range: 0-314) for children and 101 (0-480) for adults in 1999 to 202 (0-900) for children and 154 (0-500) for adults in 2021. The proportion of clinicians prescribing >40 units/kg of Standard Half Life (SHL) Factor IX concentrates for routine bleeding events in HB patients increased from 22.5% in 1999 to 50.9% in 2015, and 87.8% in 2021. The proportion of clinicians reported SHL Factor VIII usage for routine bleeding at a dose of >40 units/kg in HA patients increased from none in 1999 to 11.3% in 2015 and 29.3 % in 2021. The reported rates of prescribing an average >60 units/kg factor to treat major life-threatening bleeds increased from 67.5% in 1999 to 90.3% in 2021 for HB; rates were 2.5% in 1999, 17.3% in 2015 and 7.3% in 2021 for treating HA. For children 91% of clinicians reported prescribing emicizumab to treat HA inhibitors in patients of all ages, while >87% reported prescribing it to treat HA without inhibitor. Clinicians were more likely to always prescribe emicizumab to treat HA patients with inhibitors (63.2% for children and 57.1% for adults), as compared to always prescribing it for those without inhibitors (13.2% for children and 5.7% for adults). The most frequent reported method to treat a patient with a history of inhibitors on emicizumab who had break through bleeds was rFVIIa: 85.4% for children, and 75.6% for adults. The most frequently reported reasons for switching from FVIII to emicizumab were fewer injections/visits (87.8%), and improved patient quality of life (82.9%). Thirty-nine percent of clinicians reported caring for patients currently in gene therapy trials, 27.5% had patients who had completed gene therapy. When asked about potential future prescribing practices, 14.6% reported that they would prescribe gene therapy "all the time", 4.9% would prescribe it "about 3/4 of the time", 29.3% "about 1/2 the time", 29.3% "about 1/4 the time", and 22.0% "rarely or never". Conclusion: These data indicate changes in prescribing practices among hemophilia specialists in the US over the past 21 years. Prescribing of high doses of factor (>40 units/kg) increased, while ITI prescribing practices remained similar over time. To treat patients with major life-threatening bleeds, a larger proportion of clinicians prescribed high doses of factor (>60 units/kg) for patients with HB as compared to HA. Most clinicians frequently prescribed emicizumab for patients with HA inhibitors, but less frequently for those without inhibitors. At this time, there is wide diversity among clinicians in the expected uptake of gene therapy. Disclosures Curtis: Pfizer, Bayer, and Novo Nordisk: Consultancy; University of Southern California: Consultancy. Roberts: Takeda; Speakers Bureau: Novo Nordisk, Octapharma, Sanofi, Takeda.: Research Funding; Genentech, Novo Nordisk, Octapharma, Pfizer, Sanofi, Takeda, uniQure: Consultancy. Decker-Palmer: Genentech Inc. --A member of the Roche Group.: Current Employment, Current equity holder in publicly-traded company. Khairnar: Genentech Inc - A Member of The Roche Group: Current Employment; University of Maryland, Baltimore: Ended employment in the past 24 months; Roche: Current equity holder in publicly-traded company. Wu: Baxalta US Inc., Bannockburn, IL (a Takeda Company), CSL Behring L.L.C., Octapharma USA, Inc., Genentech Inc.: Research Funding. Nichol: Pfizer, Genentech Inc., Baxalta US Inc., Bannockburn, IL (a Takeda Company), Octapharma, CSL Behring, Global Blood Therapeutics, and Novo Nordisk: Research Funding.

Background Although combined oral contraceptives (COC) are considered a transient risk factor for venous thromboembolism (VTE), the risk of recurrence after discontinuation of anticoagulation is unclear. Few studies have focused on the risk of recurrence in this group; studies report variable results and are limited by small sample size. The risk of recurrence appears to be low, but this could relate to the young age of affected women. Deciphering the absolute VTE recurrence risk after a COC-associated VTE is crucial in helping clinicians and patients decide if anticoagulation could be discontinued after the initial treatment period. Objectives The objectives of this systematic review and meta-analysis are to estimate the incidence of recurrent VTE among women with COC-associated VTE, compared with women with unprovoked VTE. Methods We searched the following databases: Cochrane Central Register of Controlled Trial, Cochrane Database of Systematic Reviews, Embase Classic +Embase, and Medline ALL, all from the OvidSP platform, from the database's inception to July 2020. Additional studies were identified by screening citations from included studies. Prospective cohort studies, randomized controlled trials (RCTs), and meta-analyses of prospective cohort studies or RCTs were reviewed by two authors for study inclusion (Figure 1). Studies were included if women had objectively confirmed COC-associated VTE, received a minimum of three months of anticoagulation, discontinued COC prior to or at time of discontinuation of anticoagulation, time of follow-up began after anticoagulation was stopped, and recurrent VTE data was available. Studies were excluded if patients were systematically treated with an alternative pharmacologic agent intended to reduce the risk of recurrent VTE such as aspirin. Authors of identified papers were contacted for additional data on critical variables. If there were multiple publications from a cohort, the study with the longest follow up was included. Two authors extracted study data and assessed included studies for risk of bias using the Newcastle Ottawa Scale. Meta-analysis was done using a random effects Poisson regression model. Heterogeneity was assessed using the I-squared measure. Results Our systematic review included 19 studies with a total of 1,537 women (5,828 patient years of follow up) with an index COC-associated VTE, and 1,974 women (7,798 patient years of follow up) with an index unprovoked VTE. Authors contributed additional unpublished data in 16 of the 19 studies. Overall, studies were at low risk of bias, with a mean of 7 stars (out of a possible 9) in the Newcastle Ottawa Scale. Among the 19 studies, the incidence rate of VTE recurrence in women with COC-associated VTE was 1.22 per patient year (95% confidence interval (CI) 0.94 to 1.59, I 2 = 6.4%, 95% prediction interval (PI) 0.81 to 1.85) (Figure 2). The incidence rate of VTE recurrence in women with an index unprovoked VTE not associated with COC was 3.89 per patient year (95% CI 2.98 to 5.07, I 2 =74.2%, 95% PI 1.37 to 11.03). The unadjusted incidence rate ratio of recurrent VTE comparing women with COC-associated events to women with unprovoked events was 0.34 (95% CI 0.26 to 0.45, I 2 = 2.6%, 95% PI 0.26 to 0.46). Only three studies had age-adjusted comparisons, but each with a different effect measure so they could not be combined, with a relative risk ratio 0.4 (95% CI 0.2 to 0.8) (also adjusted for site of VTE and congenital thrombophilia) (Eischer 2014), a hazard ratio of 0.11 (95% CI 0.01 to 0.85) (Kearon 2019), and an incidence rate ratio of 1 (95% CI 0.3 to 3.2) (Le Moigne 2013). Conclusions The estimated risk of VTE recurrence after a COC-associated VTE is low, and is lower compared to women with unprovoked VTE, however this comparison may be confounded by age. With only a minority of studies providing age adjusted analyses, the true difference remains unknown. Our meta-analysis is strengthened by the substantial contribution of unpublished data from individual study authors. This can help to guide clinicians and patient shared decision-making on the duration of anticoagulation. Figure 1 Figure 1. Disclosures Le Gal: LEO Pharma: Honoraria; BMS: Honoraria; Pfizer: Honoraria; Bayer: Honoraria; Aspen: Honoraria; Sanofi: Honoraria. Schulman: Boehringer-Ingelheim: Research Funding; Octapharma: Research Funding. Skeith: CSL Behring: Research Funding; Leo Pharma: Honoraria; Sanofi: Honoraria.

Background In spite of the improvements in clinical care of children with Sickle Cell Disease (SCD), painful vaso-occlusive (VOC) crises, recurrent admissions and long hospital stays contribute to the disruption of the social and school life of children and adolescents with SCD causing a poor QoL. Limited information is available regarding QoL of children, adolescents and young adults with SCD and their caregivers during standard of care and after bone marrow transplantation in Italy even though Italian patients participating in international meetings or global surveys highlighted the importance to improve QoL (Strunk C. BMC Proc. 2020, Osunkwo I. Am J Hematol. 2021). Moreover, no mention is given to QoL in the current AIEOP Recommendations for the Management of Children with SCD in Italy. The availability of new treatment options for SCD highlights the need to improve QoL evaluation before and after treatments. Our Center decided, therefore, to include QoL evaluation as part of comprehensive care for patients with SCD. This study has the following aims: to describe the QoL of children, adolescents and young adults with SCD undergoing standard care or after disease curative treatments (bone marrow transplantation) and the QoL of their caregivers; to evaluate the correlation of QoL with clinical-haematological and therapeutic variables. Methods Health Related QoL was examined with the Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires in Italian: Parent Proxy Profile-49 v2.0, Pediatric Profile-49 v2.0 and 57 Profile v2.1, exploring 8 domains: Pain, Fatigue, Anxiety, Depression, Physical Abilities, Peer Relations, Sleep Disorders, Pain Interference. An English version was available for English speaking parents. Patients and caregivers accessing the SCD Clinic starting May 2021 were given the paper version of the questionnaires; due to the COVID pandemic and the limited access to the SCD Outpatient Clinic, a link to a Google online version of the questionnaires was provided to all teenagers and young adults, through their mobile devices. . PROMIS Scores were standardized through the Health Measures Scoring Service (healthmeasures.net). For the descriptive analysis, the T-score was obtained, for each patient and for each PROMIS domain (symptom or function), classifying impairment in each domain as normal, mild, moderate, or severe. The Student T Test for comparisons of the means among samples and the Wilcoxon Test for the sum of ranks were used in the statistical analysis of normal and non-normal continuous variables. For the correlation analysis between continuous variables of which at least one is not normal, the Spearman Correlation Test was used. The values with p Results All patients and parents approached accepted to perform the questionnaire. The study involved 18 caregivers and 50 patients (25% F, mean age 16.4 years, 74% HbSS, 76% from Africa): 41 undergoing standard care (7 no therapy, 34 Hydroxyurea or chronic transfusion) and 9 who received HSCT. 37 patients (74%) and 8 parents (44%) completed the online Google version of the questionnaire. The standard of care patients displayed mild to severe symptoms in various domains (Figure 1A); in the transplant population there was impairment in QoL, with less severe impairment in most of the domains, especially in the pain domains, than what was in the standard of care group. (Figure 1B). Anxiety levels and depressive symptoms were greatest between the ages of 14-26, compared to younger ages (p 0.018). Parents do not have the same perception of the disease as their children: they appeared to overestimate the domain of pain and fatigue and underestimate anxiety and depression (p The number of hospital admissions in the previous year correlated with worse QoL (p 0.04), while the number of painful VOC showed a tendency towards significance (p 0.07); there was no difference with the other domains. Updated results will be presented. Conclusions Our data show the feasibility of evaluating QoL during routine visits and also remotely. Impairment of QoL is already present in a subgroup of young patients. Even after HSCT, QoL is not optimal but personal, social, and economic reasons need to be taken into account to adequately interpret the results. Longitudinal assessment to look at QoL will be important. Figure 1 Figure 1. Disclosures Biffi: BlueBirdBio: Consultancy, Other: Advisory Board. Colombatti: Global Blood Therapeutics: Consultancy; BlueBirdBio: Consultancy; NovoNordisk: Consultancy; Novartis: Consultancy; Forma Therapeutics: Consultancy; Addmedica: Consultancy; Global Blood Therapeutics: Research Funding; BlueBirdBio: Research Funding.

Background: Allogenic hematopoietic stem cell transplant (HSCT) is the potentially curative treatment in intermediate-high risk acute myeloid leukemia (AML). Relapse is the major cause of treatment failure and about 50% of AML patients relapse after the HSCT. Venetoclax is a B-cell lymphoma-2 (BCL-2) inhibitor that can restore activation of apoptosis in malignant cells. The FDA has approved venetoclax for the treatment of newly diagnosed adult AML patients unfit for intensive chemotherapy. We present a systemic review aimed to evaluate outcomes with venetoclax in patients with relapsed AML after HSCT. Methods: We performed a literature search on 3 databases (Pubmed, Cochrane, and Clinicaltrials.gov) following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using the Mesh terms "leukemia, myeloid, acute" OR "myelodysplastic syndromes" OR "hematopoietic stem cell transplantation" AND "venetoclax." After excluding duplicates and non-relevant articles, 161 studies including the case reports, review papers, and clinical trials were identified, and 7 studies were included in the analysis. Quality evaluation was done using the NIH quality assessment tool. Pooled analysis was done using the 'meta' package (Schwarzer et al, R programming language) and proportions with 95% confidence intervals (CI) were computed. The Inter-study heterogeneity among the studies was assessed using the Q statistic proposed by Cochrane and the I 2 index introduced by Higgins and Thompson. Results: Of 7 included studies, only 2 studies reported outcomes with the use of venetoclax in relapsed AML after HSCT and the rest of studies reported outcomes in all relapsed AML patients. (Table 1) Complete response (CR) with or without hematological recovery (CRi) was reported in 37% of patients (95% CI 24-52, I 2=75%, n=225). Morphologic leukemia free state (MLFS) was noted in 14% of patients (95% CI 0.08-0.22, I 2=31%, n=190) with an overall response rate (ORR) of 55% (95% CI 0.40-0.70, I 2=78%, n=220). Conclusion: Venetoclax has showed promising results in relapsed AML, but there is very limited data evaluating the role of venetoclax after HSCT in relapsed AML. Venetoclax is increasingly used off-label after HSCT in relapsed AML and our findings highlight the need for prospective studies to evaluate the safety and efficacy of venetoclax in this patient population. Figure 1 Figure 1. Disclosures Anwer: GlaxoSmithKline: Research Funding; BMS / Celgene: Honoraria, Research Funding; Allogene Therapeutics: Research Funding; Janssen pharmaceutical: Honoraria, Research Funding. Abhyankar: Incyte/Therakos: Consultancy, Research Funding, Speakers Bureau. McGuirk: Allovir: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Novartis: Research Funding; Bellicum Pharmaceuticals: Research Funding; Astelllas Pharma: Research Funding; Gamida Cell: Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Pluristem Therapeutics: Research Funding.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause severe vascular complications associated with endothelial dysfunction and systemic inflammation. COVID19-specific IgG are detectable within a week of infection. Long COVID-19 has been described in patients continuing to exhibit symptoms after the virus is no longer detectable in the respiratory secretions, including fatigue, dyspnea, headache, and brain fog. The recent FAIR Health study reviewed a total of 1,959,982 COVID-19 patients for the prevalence of long COVID symptoms and reported that 23.2% had at least one post-COVID symptom [1]. The underlying biologic mechanisms of long COVID remain unclear, thus treatments are limited to symptomatic relief and supportive care. Many long COVID symptoms are consistent with systemic inflammation and impaired oxygen delivery observed in individuals with sickle cell disease (SCD), in turn associated with elevated blood cell adhesion and decreased red blood cell (RBC) stability. The aim of this study was to determine if deleterious changes in in blood cell properties related to adhesion and membrane stability under stress can be associated with the symptoms of long COVID-19. In this work we evaluated 7 SCD patients that were diagnosed with SARS-Cov-2 and tracked their recovery using semiquantitative IgG and blood cell function assays. Methods: Blood samples were collected by the Foundation for Sickle Cell Disease (SCD) Research from SCD (homozygous SS, n=6) patients coming for regular or urgent clinic visit with SARS-CoV-2 serological and blood cell functions tests performed per the standard of care. Semiquantitative IgG assay was performed using DXi-80 (Beckman Coulter). Flow adhesion of whole blood to VCAM-1 (FA-WB-VCAM)and P-Selectin (FA-WB-Psel) substrates were determined by counting the cells that remain adherent in a microfluidics channel after perfusion with whole blood 1:1 diluted with HBSS buffer and washed by reversed flow at 1 dyne/cm 2. Red blood cell mechanical fragility (RBC MF) was measured as hemolysis induced by an oscillating cylindrical magnet with periodic non-invasive probing of cell-free hemoglobin fraction. Six individuals with SCD recovering from SARS-Cov-2 with biomarker data available both before and for more than 3 months after the infection (179±62 days) were included in the study. Results: IgG levels varied from less than 0.1 to 37, with positive values being defined as IgG > 1. The median estimated half-life of IgG decline was 53 days ranging from 25 to 90 days (the last, for the hospitalized patient). Averaged for IgG positive (IgG+) and IgG negative (IgG-) conditions, combining pre- and post-infection IgG- conditions, values of patient hemoglobin (Hb), FA-WB-VCAM, FA-WB-Psel, and RBC MF cell properties lacked statistical significance (under both a paired t-test and population statistics). Hb levels remained essentially unchanged regardless of the time from infection or IgG status. However, FA-WB-VCAM, FA-WB-Psel, and RBC MF were all significantly elevated after SARS-Cov-2 seroconversion and remained elevated despite declining IgG levels (e.g., Fig. 1). These increases in biomarker values were statistically significant for both FA-WB-VCAM and RBC MF, and were approaching significance for FA-WB-Psel (p Conclusions: Whole blood adhesion to both p-selectin and VCAM-1 as well as RBC membrane stability can be significantly impaired in convalescent SARS-Cov-2 patients suggesting an association with long COVID-19. New and emerging treatments that modify whole blood adhesive properties and RBC membrane stability should be investigated for their potential to accelerated recovery from long COVID-19. Health F. A Detailed Study of Patients with Long-Haul COVID: An Analysis of Private Healthcare Claims; White Paper. June 15, 2021 Disclosures Tarasev: Functional Fluidics: Current holder of stock options in a privately-held company. Ferranti: Functional Fluidics: Current holder of stock options in a privately-held company. Allen: Functional Fluidics: Current Employment. Gao: Functional Fluidics: Current Employment. Topping: Functional Fluidics: Current Employment. Ferranti: Functional Fluidics: Current Employment. Makinde-Odesola: Functional Fluidics: Other: conduct research for academic program. Hines: Functional Fluidics: Current holder of stock options in a privately-held company.

Background: Graft-versus-Host Disease (GVHD) is a complication that occurs in 30-70% of hematologic malignancy patients post-hematopoietic stem cell transplant (HCT) (Flowers, February 2021). Steroid refractory GVHD has led to studies approving ruxolitinib and ibrutinib as the first FDA approved therapies for steroid refractory GVHD. Ruxolitinib is approved to treat acute GVHD (aGVHD) and inhibits Janus associated kinase (JAK). Ibrutinib is approved to treat chronic GVHD (cGVHD) and functions by inhibiting Bruton's tyrosine kinase (BTK). Here we describe 2 cases of patients who received both drugs for their GVHD. Patient #1 was a 4-year-old female who had a diagnosis of NK cell dysfunction. The patient underwent a conditioning regimen with melphalan 140 mg/m2, fludarabine 30 mg/m2 X5, and alemtuzumab for 5 days. The allogeneic HCT was performed with cells from a 9/10 NMDP donor and received a CD34+ enrichment with T cell addback of 2.1 x10^5 CD3/kg. Tacrolimus was given for GVHD prophylaxis. The patient developed aGVHD stage 2, grade 3 of the gut on day +148. Patient received steroids, extracorporeal photopheresis (ECP), and cellcept, and the GVHD resolved. The patient then developed skin GVHD on day +189 (stage 1, grade 3) that resolved. Approximately 15 months post-transplant there was concern the patient was developing cGVHD of the skin and gut (chronic though stable diarrhea), and therefore ibrutinib was initiated day +490 at 140 mg daily. The cGVHD persisted despite ibrutinib, ECP, tacrolimus, and sirolimus. Ruxolitinib was then initiated 2.5 mg bid on day +883. Patient demonstrated stable to slightly improved GVHD and tapered ibrutinib to 110 mg between days +951 and +980. The patient remained on ruxolitnib and ibrutinib as of day +1172. Patient #2 was a 1-year-old male with sickle cell anemia. The patient was transplanted under a haploidentical protocol from the mother, receiving a CD34+ enrichment with T cell addback of 2x10^5 CD3/kg. The conditioning regimen was busulfan 2 mg/kg, fludarabine 30 mg/m2, cyclophosphamide 50 mg/kg, and thymoglobulin 2 mg/kg with tacrolimus as GVHD prophylaxis. Patient was experiencing fevers, dyspnea and CT was concerning for an infiltrative process. Broad spectrum antibiotics did not improve symptoms. A lung biopsy was performed and bronchiolitis obliterans organizing pneumonia (BOOP) was diagnosed on day +217 (pathology confirmed GVHD). The pathology report was reviewed at an outside institution, raising the question of thrombotic microangiopathy (TMA) in context of hemolysis markers (high LDH and low platelets). Patient was placed on Fluticasone, Azithromycin, and Montelukast (FAM). Due to persisting BOOP confirmed on lung biopsy on day +407, the patient started ibrutinib 140 mg daily on day +411 and was started on ruxolitinib 2.5 mg bid on day +412. ECP commenced on day +414. Within 1 month, symptoms improved. Lung CT imaging appeared stable since initiation of these modalities. Patient continued with ruxolitinib, ibrutinib and ECP (twice per week) for GVHD, though the ruxolitinib dose was tapered in half starting day +477. Symptoms have improved. Discussion: To our knowledge this is the first reported case series of concomitant use of ruxolitinib and ibrutinib. A literature search (PubMed and abstracts in society meetings) was conducted that found 1 paper focused on ruxolitinib for cGVHD with 3 patients on concomitant ibrutinib, but without further details (Ferreira et al., June 2021). Our cases represent a proof-of-concept approach to GVHD management and demonstrate the feasibility of administrating both agents. The combination was well-tolerated with no significant adverse events noted. Neither patient had to discontinue due to poor tolerance or interactions. We expect this dual-drug therapy will become more common going forward given FDA approvals for both ruxolitinib and ibrutinib. Recently, ruxolitinib underwent a successful trial for glucocorticoid-refractory cGVHD when compared to best available therapies, including ibrutinib, though the drugs were not tested in combination (Zeiser et al., July 2021). These findings may open the door for further concomitant use, especially if ruxolitinib is approved by the FDA for cGVHD. We propose further investigation into dual therapy of these drugs in cGVHD either compared to steroids or as a second line option. Disclosures Cairo: Jazz Pharmaceutical: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Speakers Bureau; Sanofi: Speakers Bureau; Servier: Speakers Bureau; Sobi: Speakers Bureau; Omeros: Membership on an entity's Board of Directors or advisory committees; Nektar: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Ruxolitinib is being used here for chronic GVHD, while it is FDA approved for acute GVHD.

Introduction: Sickle cell disease (SCD) causes devastating complications that can affect any organ in the body. Particularly, SCD can present with neurological complications of overt strokes, silent infarcts and cognitive impairment. As patients are living longer with SCD, cognitive functioning is an important aspect of their disease as deficits can impact education, employment, or adherence to medications. Most of the studies assessing cognitive impairment in this population have been in children with limited data on adults. This study explored the results of cognitive testing in adult patients with SCD when compared to normative data. This study also sought to determine any association between psychological factors (baseline anxiety and depression) as well as biological factors (i.e. hemoglobin levels). Methods: This was a cross-sectional study conducted at the Sickle Cell Center of Southern Louisiana in New Orleans.The study included adults with a diagnosis of sickle cell disease regardless of subtype who were over the age of 18. Patients were excluded if they were not able to physically complete the tasks. Executive function, memory, psychomotor speed, and memory were assessed using the following tasks from standardized pencil-and-paper cognitive tasks from the Cambridge Neuropsychological Automated Battery (CANTAB) test: Stocking of Cambridge (SOC),Delayed Matching to Sample (DMS), Paired Associates Learning (PAL), Motor Screening Task (MOT), Intra-Extra Dimensional Set Shift (IED), Spatial Working Memory (SWM). The Hospital Anxiety and Depression Subscale (HADS) clinical assessment tool was used to screen for anxiety and depression at the time of testing. A HADS score >8 denotes significant anxiety or depression. Results: A total of 22 patients (59% females, mean age 29.6±2.1 years) were included in this study. Attention and psychomotor speed were relatively preserved cognitive domains with 59.1% of patients scoring greater than 75 thpercentile relative to normative mean. Conversely, executive functioning often appeared impaired with 72.7% and 77.3% of patients scoring below 25 thpercentile in outcome measures of IED and SWM, respectively. Similarly, a significant percentage of patients scored below 25 thpercentile in outcome measures of visual memory, PAL and DMS, 63.6% and 45.4%, respectively. Fifteen participants (68%) screened positive for anxiety while two screened positive for depression. Patients with anxiety tended to perform worse on most cognitive tasks, although the differences in scores did not reach statistical significance. Additional analyses of association of biologic factors and neurocognitive functioning are currently underway. Discussion and Conclusion: Our results support that adults with sickle cell disease often suffer from cognitive deficits, which was expected based on pediatric studies demonstrating cognitive impairment in children with SCD. Interestingly, we observed a predominance of poor executive function over changes in attention and psychomotor speed in this study. This is in contrast with what providers familiar with "mini mental assessment" for dementia may expect. Typical dementia patients develop attention and memory changes before executive function is affected. Therefore, it is possible that cognitive impairment in SCD may go by unnoticed without proper testing. Additionally, in this cohort, anxiety was frequent and tended to associate with worse performance. Since this is a cross-sectional study, it is unclear whether cognition is progressively impaired over the years. Prospective studies are required to help determine whether and how fast progression occurs and what risk factors are implicated in the development and progression of cognitive impairment. Such deficits have been demonstrated to be associated with difficulties around employment and adherence to medication, which ultimately jeopardizes long term outcomes. Overall, we recommend neurocognitive and psychological evaluations as part of the routine care for adult SCD patients since abnormal findings seem common and may not be obvious without adequate testing for different domains. Treatment of anxiety disorder and cognitive rehabilitation may prove helpful to improve cognition in SCD patients. Disclosures Fertrin: Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kruse-Jarres: Genentech/Roche: Speakers Bureau; Pfizer: Consultancy; CSL Behring: Consultancy; CRISPR: Consultancy; Biomarin: Consultancy; Genentech: Consultancy, Research Funding.

Use of Cryopreserved Allogeneic PBSC Results in Delayed Engraftment And Increased Incidence of Poor Graft Function Introduction: During COVID Pandemic, national and international transplant centres agreed to use cryopreserve the donor PBSC as a safer option to deliver allogeneic transplants. Published data suggests that use of cryopreserved allogeneic PBSC is safe and comparable to use of fresh PBSC but cryopreservation of stem cells may lead to cell loss and hence efficacy. During COVID pandemic, use of cryopreserved allogeneic PBSC was adopted as policy on 01/06/2020. This look back analysis evaluates the impact of change in policy. Aims: Evaluate Engraftment time, compare with historical data, blood component support, and use of growth factors Methods and Materials: Data was collected from health records (paper and electronic) and laboratory records. Transplant features and engraftment kinetics were analysed. Results: Group A June 2020 to November 2020, 19 patients [M: 13; F: 6; median age: 50yr (range: 23-69)] who received cryopreserved allogeneic PBSC were compared to 35 patients [M:24; F:11; median age: 59yr (range: 21-71)] receiving fresh allogeneic PBSC for engraftment kinetics. There were no differences between two groups regarding underlying diagnosis (p=0.31), sex mismatch, CMV mismatch, blood group mismatch, reduced intensity conditioning [RIC](p=0.28), type of donor (p=0.98) or use of Alemtuzumab (p=0.88). Median infused Cell dose in group A was 5.3 (3.4-7.16) and in group B 4.9 (1.03-6.85), [p=0.11]. Neutrophil engraftment was significantly faster with fresh PBSC as compared to cryopreserved PBSC (16d vs. 25d, p=0.0025) predominantly with MUD (18d vs. 27d, p=0.009) and RIC (16d vs. 25d, p=0.009). Platelet engraftment to 25 was faster with fresh PBSC (13d vs. 20d, p=0.021) with delayed engraftment in MUD (20d vs. 13d, p=0.006) and RIC (23d vs. 13d, p=0.039). Day to engraftment per unit CD34 was shorter with fresh PBSC for neutrophils (median: 3.2, range: 2.0-7.7 vs. 5.3, range: 2.5-16.7; p=0.006) and platelets (median: 2.4, range: 1.7-25 vs. 3.8, range: 2.2-25; p=0.001) but only for MUD. This suggests 35-40% less efficiency with use of cryopreserved PBSC. There was no difference in the need for transfusion support [RBCs (6 units vs. 3 units, p=0.32); platelets (5 pools vs. 7 pools, p=0.33)]. G-CSF use was higher with cryopreserved PBSC in RIC (54% vs. 20%, p=0.031). Two patients experienced TRM before day 90 (3.7%). At day 90, 17/52 (32.7%) had cytopenia in one lineage and 8/52 (16%) had cytopenia in more than one lineage. Delayed engraftment was observed in 10 of 33 patients (30.3%) transplanted in 2020 and the only significant association was use of cryopreserved PBSC (0% vs. 53%, p=0.001). There was no difference in the incidence of aGVHD, hepatic VOD, microangiopathy and bacterial infections. Numbers are not sufficient to make disease specific comparisons. Conclusion: Cryopreserved PBSC result in delayed neutrophil and platelet engraftment predominantly with MUDS and RIC. Incidence of delayed engraftment and poor graft function is higher. Per unit CD34 dose, cryopreserved PBSC are 30-40% less efficient to achieve engraftment. Delayed engraftment with cryopreserved PBSC especially in MUD raises the possibility that time from harvest to cryopreservation contributes to reduced efficacy. Based on these findings it was decided to infuse higher CD34 dose (6-7x10^6/kg as compared to usual 4-5x10^6/kg) for cryopreserved MUD PBSC. Disclosures Bloor: Kite, a Gilead Company: Honoraria; Novartis: Honoraria.

T-cell acute lymphoblastic leukaemia (T-ALL) is an aggressive hematologic malignancy arising from the transformation of immune T-cell lymphocytes. Early T-cell progenitor (ETP-ALL) is a subgroup particularly associated with chemoresistance and a high risk for relapse. Recently, it was shown that ETP-ALL is dependent on the expression of the anti-apoptotic protein BCL-2, and is sensitive to inhibition with ABT-199, a BCL-2 specific BH3 mimetic 1,2. However, one issue with a targeted agent, such as ABT-199, is the development of acquired resistance. Interestingly, there have been numerous high impact papers connecting ABT-199 resistance to altered oxidative phosphorylation (OXPHOS) 3,4. While there are relatively few studies into T-ALL metabolism, there is evidence that aerobic glycolysis, the conversion of glucose to lactate, is greater in proliferating T-cells than in T-ALL and that NOTCH signalling can drive mitochondrial OXPHOS 5. A recent study showed that the transcription factor RUNX2 altered T-ALL metabolism, increasing both glycolysis and OXPHOS and enhancing leukemic cell migration 6. However, there has been relatively little research into the metabolic profile of T-ALL at distinct stages of differentiation. The aim of this study was to determine the role of ABT-199 resistance in altering metabolism and determine if that was due to the differentiation state of the T-ALL. ABT-199 R LOUCY cells were generated by chronic exposure to increasing concentrations of ABT-199 administered every two days. The EZH2 KO Jurkat cell lines were previously generated through CRISPR-Cas9 engineering 7. In order to assess the metabolic profile, cells were attached to a 96 well plate using CellTak and the extracellular acidification rate (ECAR) and oxidative phosphorylation (OXPHOS) was measured on a Seahorse Bioscience XF96 Extracellular Flux Analyzer. Anti-apoptotic dependence was measured using BH3 profiling and cell death by Annexin V/propidium iodide staining. The mitochondrial structure was visualized using transmission electron microscopy. Previously, we generated ABT-199 resistant ETP-ALL LOUCY cells (ABT-199 R) following continuous exposure to ABT-199 over a prolonged period of several months 8. The ABT-199 R cells showed dependence on BCL-XL for survival and sensitivity to the BCL-XL inhibitor WEHI 539. The ABT-199 R cells showed evidence of differentiation to a more mature T-cell. The ABT-199 R cells had increased surface CD3 (sCD3) expression and CD1A expression, along with increased expression of TAL1 and LMO2 genes compared to parental LOUCY cells. Interestingly, the ABT-199 R cells showed enhanced basal respiration, ATP production and max respiration compared to the parental cells. Indeed, analysis of the expression of OXPHOS complexes showed increased expression of complexes I-IV in the ABT-199 R cells, compared to the parental controls. Indeed, the parental LOUCY cells appeared to have reduced cristae number and length compared to the ABT-199R cells. Next, we assessed if inhibiting OXPHOS with a series of inhibitors (oligomycin, rotenone, antimycin) could sensitize the ABT-199 R LOUCY cells to ABT-199. However, we did not detect any changes to sensitivity of ABT-199. This led us to hypothesize that perhaps the changes in OXPHOS were due differentiation state of the LOUCY cells. We confirmed that more typical T-ALL cell lines (JURKAT and CEM-CCRF) had higher OXPHOS than the ETP-ALL cell line LOUCY and had higher expression of the OXPHOS complexes I-IV by Western blotting. To assess if de-differentiation of a more typical T-ALL cell line would cause a reduction in OXPHOS we turned to the EZH2 knockout (K/O) Jurkat cells 7. We found that EZH2 KO2 showed a reduction in the differentiation markers CD1A and CD3 on the cell surface and TAL1 gene expression, compared to WT control Jurkats. Next, we assessed the OXPHOS and found that the de-differentiated EZH2 cells had reduced OXPHOS compared to the parental controls, with altered mitochondrial structure. Suggesting, that de-differentiation of typical T-ALL cell line reduces OXPHOS. In this study we show that metabolic phenotype is linked to the maturation stage of T-ALL. We believe that the altered metabolism identified in ABT-199 resistance is linked to the selection of a more mature cell type. Highlighting, that altered metabolism may not be a driver of resistance to ABT-199 but a consequence of the maturation stage of the resistant cell. Disclosures Di Grande: Novartis: Current Employment. Leon: BenevolentAI: Current Employment. Mansour: Astellas: Consultancy, Honoraria; Janssen: Consultancy. Bond: Haematology Association of Ireland Award funded by Novartis: Research Funding. Ni Chonghaile: AbbVie: Research Funding.

Introduction. Monoclonal Gammopathy of Undetermined Significance (MGUS) is a pre-malignant plasma cell disorder reported in approximately 3% of individuals aged > 50 years, characterized by a low risk (about 1% per year) of evolution into "overt" myeloma or other lymphoproliferative diseases. It is classified as IgM-MGUS (15%) and non-IgM-MGUS (80-85%). MGUS is usually asymptomatic, but a higher risk of deep venous thrombosis and infection has been reported. In March 2020, "Coronavirus Disease 2019" (COVID-19) outbreak has been declared a pandemic by the World Health Organization. Regarding outcome of COVID-19 in patients with plasma cell dyscrasia, many papers have been published about multiple myeloma (MM), reporting a higher fatality rate respect to general population, while few data are available about the outcome of SARS-CoV-2 infection in patients with MGUS. Methods. We collected clinical data on MGUS Apulian patients with SARS- CoV-2 infection, tested by RT-PCR on nasopharyngeal swabs between March 1st, 2020 and April 30st, 2021. Among 1454 MGUS patients followed at our center, 91 were found SARS-CoV-2 positive, enrolled in this observational, retrospective study and compared with 182 age and sex-matched normal controls. Clinical data collected regarded: symptoms, hospitalization, hospitalization in intensive care unit, death. Calculations were carried out using Stata MP17. Results. Mean age of whole group (n. 273) was 65,3+/-13,3 years (range: 29-89), with no statistically-significant differences (p=0,734) observed between MGUS-group (65,6+/-13,3; range: 29-89 years) and controls-group (65,2+/- 13,4; range: 29-89 years). Mean number of comorbidities in the whole group was 1,2+/-1,2 (range: 0-5) and no statistically-significant differences (p=0,844) were found between MGUS-group (1,3+/-1,3; range: 0-5) and control group (1,2+/- 0,9; range: 0-3). About MGUS-subtypes, the most frequent was IgG-kappa (n=36; 39,6%), followed by IgG-lambda (n=27; 29,7%) and IgM-kappa (n=6; 6,6%). Regarding MGUS risk-stratification, application of Mayo Clinic model identified 22 patients (24,2%) with low risk, 22 (24,2%) with low-intermediate risk, and 3 (3,3%) with high-intermediate risk; in 44 patients (48,3%) this data was missing. Immunoparesis was present in 13 cases (14,3%) and absent in 55 (60,4%), missing in 23 (25,3%). No patient developed MM or a lymphoproliferative disease progression during and immediately after COVID-19. Rates of symptoms (59,3% vs 56%), hospitalization (20,9% vs 14,3%), hospitalization in intensive care unit (11% vs 8,8%) and death (8,8% vs 5,5%) were slightly higher in MGUS group than controls (Table 1), but these differences were not statistically significant. A statistically significant association (p Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

The small cell variant of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (SC-ALCL) is a subtype defined as comprising two distinct tumor cell populations in immunohistochemistry: small cells staining negative or weakly positive for ALK and CD30 protein; and large cells staining strongly positive for those proteins. Although the constitution of these two different cell populations might contribute to the poor prognosis, detailed characterization of each population by molecular-based approaches has not been done due to the difficulty of cell separation from solid tumor sample. In this paper, we have analyzed the characterization of each tumor cell population using the patient sample from SC-ALCL leukemic phase obtained from peripheral blood by molecular-based approaches. Flow cytometric analysis revealed two distinct abnormal populations. The major population comprising 74% of total leukocytes was positive for CD3 and CD8, and negative for CD4, CD5, CD25 and CD30. The minor population comprising 5% of total leukocytes was positive for CD25, CD30, CD11b and CD13. Fluorescent in situ hybridization with ALK break-apart probes and RT-PCR analysis confirmed that most of the cells including both populations were rearranged with NPM-ALK gene. To elucidate the cause underlying the distinct levels of ALK protein expression in each population, we separated those tumor cells by CD30-PE antibody and a magnetic bead separation kit, extracted DNA and RNA from each population, and compared NPM-ALK mRNA expression levels by droplet digital polymerase chain reaction. The expression level of NPM-ALK mRNA in the CD30-negative population was ten-fold less than that in the CD30-positive population (Table). This result indicated that the two tumor cell populations expressed the distinct level of NPM-ALK mRNA, although both populations possessed NPM-ALK fusion gene. To assess the effectiveness of various chemotherapies in each tumor cell population, we monitored each population in peripheral blood by flow cytometric analysis (small cell; CD30-5-8+, large cell; CD30+) over time. Intriguingly, CD30-negative population behaved as chemo-resistant cells in clinical course, however alectinib, a second-generation ALK-inhibitor, eradicated both populations inducing first complete remission. This study revealed two definitive features regarding the small CD30-negative population of SC-ALCL, with a lower expression level of NPM-ALK mRNA transcripts and chemoresistance. The cause of distinct ALK staining levels in immunohistochemistry was revealed depending on the distinct expression level of NPM-ALK mRNA transcripts. Finally, since both populations were sensitive to ALK-inhibitor, early administration of ALK-inhibitor might be the reasonable option for SC-ALCL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

BACKGROUND The rate of major arterial and venous thrombosis in primary myelofibrosis (PMF) and post-ET (PET) and post-PV (PPV) secondary myelofibrosis has been evaluated in a limited number of studies. In the present paper we describe the clinical epidemiology of thrombosis in a large series of patients with overt PMF and PPV/PET MF looking at the rate and risk factors. Moreover, we report findings on thrombosis rate in two cohorts of patients treated with Hydroxyurea (HU) or Ruxolitinib (Ruxo). METHODS Patients were registered in the European Registry for Myeloproliferative Neoplasms (ERNEST). This project, promoted by the European LeukemiaNet, is coordinated by FROM - Foundation for Research, Papa Giovanni XXIII Hospital, Bergamo (Italy) and supported by Novartis through a research collaboration . Patients were diagnosed in 6 Centers from Italy, Spain and Sweden, between Jan, 2001 and Dec, 2012, with the required follow-up information. Patients (n= 1010) with PMF (n=584, 59%), PET-MF (n=207, 20%) and PPV-MF (n=219, 21%) were evaluated for incident thrombosis as primary endpoint. Considering death as a competitive event, uni-and multivariate analyses were performed by applying Fine & Gray competing-risk regression models. RESULTS After a median follow-up of 3.8 years (IQR: 1.8-7.1) from diagnosis, 108 thromboses (10.7%) occurred, for an overall incidence rate of 2.0% pts-yr (95% CI: 1.7-2.5). Arterial thromboses were found in 50 patients (46.3%) including cerebral (n=21, 19.4%), myocardial infarction (n=13, 12.0%) and peripheral events (n=9, 8.3%). Venous thromboses were 58 (53.7%), of which 25 (23.0%) were DVT ± PE and 11 (10.2%) were splanchnic. Thrombosis rate was 1.91, 1.60 and 2.79% pts-yr in PMF, PET-MF and PPV-MF, respectively. In univariate analysis, factors significantly associated with an increased thrombotic risk in PMF were age (p=0.013) and the presence of the JAK2 mutation (p=0.003); in addition, a significant higher proportion of PMF patients at low and intermediate-1 vs intermediate-2 or high risk IPSS score, had thrombosis during the follow-up (p=0.008). In multivariate analysis, only JAK2 mutation retained statistical significance (SHR=3.12, 95% CI: 1.40-6.94, p=0.005). Conversely, neither in univariate nor in multivariable analysis, significant risk factors were not found.To investigate the possible interaction of IPSS score and JAK2 mutation we created a model whose results are presented in Fig. 1A: the cumulative incidence function (CIF) of thrombosis was significantly lower in patients with JAK2 wild-type and intermediate-2 or high IPSS score (CIF: 4% projected at 10 years; SHR=1 [reference category]), while patients at the highest risk for thrombosis harbored JAK2 mutation and were categorized at low or intermediate-1 by IPSS score (CIF: 20% projected at 10 years, SHR=7.13, p=0.008). Of note, thrombosis had a significant impact on mortality. After adjusting for sex, age, year of diagnosis, type of MF and IPPS, HR was 1.51, (95% CI. 1.15-1.98, p=0.003).The influence of drug exposure to incident thrombosis was investigated in two cohorts of 559 consecutive patients exposed to HU (n=470) or to Ruxo (n=89), median treatment 2.6 and 3.0 years, respectively. HU- compared to Ruxo-treated patients were older (median age 67 vs. 63 years, p=0.001), more frequently triple negatives (12% vs. 2%, p=0.036), less splenomegalic (spleen length >10 cm: 30% vs. 88%, p CONCLUSION IPSS score, in addition to the survival risk assessment, may be useful, if associated with the JAK2 mutation, to recognize patients at vascular risk and to suggest appropriate anti-thrombotic prophylaxis. The trend towards a benefit of Ruxo, compared to HU, warrants a study in larger case series. Figure 1 Figure 1. Disclosures Barbui: AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Passamonti: Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Speakers Bureau. Vannucchi: Incyte: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Lectures; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Lectures; AbbVie: Membership on an entity's Board of Directors or advisory committees, Other: Lectures.

Background: Philadelphia negative Myeloproliferative neoplasms classically characterized by excess production of terminal myeloid cells in the peripheral blood. Among this group, primary myelofibrosis is the least common and usually carries the worst prognosis. Bone involvement in primary myelofibrosis has many forms and tend to manifest as osteosclerotic lesions in vast majority of cases, however osteolytic lesions are reported in exceptional occasions. In this review, we tried to shed the light on this rare association. Methods: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the English literature (Google scholar, PubMed, and SCOPUS) for studies, reviews, case series, and case reports about patient with myelofibrosis who develop lytic bone lesion. We used the terms in combination: "Myelofibrosis'" or "Primary myelofibrosis" OR "chronic idiopathic myelofibrosis" OR "agnogenic myeloid metaplasia" and "Osteolytic bone lesion", "Osteolytic lesion", "lytic bone lesion". The review included patients with primary myelofibrosis confirmed by biopsy. The reference lists of the included studies were scanned for any additional articles. The search included all articles published up to 10th April 2021. Two independent reviewers screened the titles and abstracts of the records independently and papers unrelated to our inclusion criteria were excluded. A total of 13 articles were included in the review. Results : Total of 13 patients were included in the review. 7 patients were males, male to female ratio almost of 1:1. The mean age at time of diagnosis was 57.69 year, only two cases were diagnosed at young age, however the majority have osteolytic bone lesion at age above 50 years (12/13) of cases. The mean time between the diagnosis of primary myelofibrosis until the osteolytic bone lesion capturing was approximately 8.8 years. 9 out of 13 patients have painful bone lesion, others were incidental finding during a scan for other reasons. All patients have significant splenomegaly. All patients had the lytic lesion detected on x ray, and 2 patients had confirmed findings on magnetic resonance imaging (MRI). The most common affected bones were the vertebrae, pelvis, ribs, humerus then the scapula, femur and skull and less frequently wrist bones and calcaneus. Only one case has reported involvement of the tibia and fibula. The shape, the extension and the numbers of lesion were variable, some showed cortical sparing and others come with cortical destruction. 10 out of 13 cases have confirmed the nature of the osteolytic lesion containing hematopoietic stem cells with or without fibrosis, 2 cases were positive for JAK2 mutation. 2 patients have received ruxolitinib, one of them preceded with bone marrow transplant, others received nonspecific therapies. Discussion: The hyperdynamic ineffective bone marrow can have a negative impact on the bone structure resulting in different types of bone pathology including lytic and sclerotic lesions. The exact mechanism beyond developing lytic lesions is not fully studied, observations revealed two possible causes: systemic inflammation and direct mechanical compression from para-osseus lymph nodes. Lesions prevalence was equal in both genders which can be attributable to a small sample size, in addition, most of the patients were in advanced stages when the lytic lesions discovered and this observation can be explained by the needed time to generate extramedullary hematopoiesis and its subsequent effect on bone structure. The variation in time between the diagnosis of PMF and development of osteolytic bone lesions could be due to the indolent phase of the disease, in which patients can survive for decades without symptoms. Until recently the treatment of myelofibrosis was supportive, but after establishing the JAK2-stat pathway role in myeloproliferative disorders the FDA approved ruxolitinib a JAK2 inhibitor which shows not only survival benefit but also has a significant impact on the resolution of the lytic bone lesions as well. conclusion Osteolytic bone lesions in patients with primary myelofibrosis is extremely rare finding, and noticed shortly after diagnosis in elderly and after longer duration in young patients. The lytic lesion seems to have a bad prognostic value as we can notice 11 out of 13 patients died within one year of detection. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

The expression rate of CD38 in acute myeloid leukemia is high. It is reported that the expression of CD38 in myeloid leukemia is stable and can be used as a potential therapeutic target for leukemia. Daratumumab is a therapeutic drug targeting CD38. It is widely used in myeloma, but it has not been applied in AML. The prognosis of 4 patients with acute myeloid leukemia treated with CD38 monoclonal antibody combined with demethylating drugs / traditional chemotherapy was reviewed. Patient demographic data and clinical characteristics see table 1. One patient with de novo AML in the high-risk group achieved remission after Dara combined with azacytidine and venetoclax. The other three patients were suffering Relapsed/Refractory AML. Two of them achieved remission after Dara combined with azacytidine and venetoclax. The patient, who was non-remission after Dara combined with IA chemotherapy (Idarubicin, Cytosine Arabinoside), achieved remission after CART targeting CD38. In this paper, four cases were reported, and the rationality of CD38 targeted therapy was further analyzed. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.