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Polycythemia vera (PV) is a Philadelphia-negative myeloproliferative neoplasm characterized by excessive myeloid cells production, mostly secondary to mutations in the Janus kinase 2 (JAK2) gene. PV natural history might be burdened by thrombotic events (TEs) and evolution into post-PV myelofibrosis (PPV-MF) or blast phase (BP). To date, no treatment strategies have been shown to have disease modifying effects, so therapy is directed at preventing TEs. All patients require phlebotomies (PHLs) to keep hematocrit below 45% and once-daily low dose aspirin (if not contraindicated). Apart from patients at "high risk" because of age over 60 years or a thrombosis history, cytoreductive therapies (CT) should be given to patients with relevant signs of myeloproliferation or intolerance to PHLs. Approved choices both for first and second line CT are hydroxyurea (HU) and pegylated forms of interferon (peg-IFN), the latter probably being better for young patients, and subjects without critical and recent vascular events or massive splenomegaly. The JAK1/2 inhibitor ruxolitinib is the treatment of choice in case of resistance/intolerance to HU, with proved efficacy in terms of thrombotic prevention. Data are too preliminary to consider CT for "low risk" PV cases, but ropeg-IFN is being studied in this setting with a short follow-up. A careful monitoring for signs of evolution into PPV-MF is fundamental for optimizing patient management.

Objectives: Treatment of older patients with acute myeloid leukemia (AML) is still controversial. To facilitate treatment decisions, the “fitness criteria” proposed by Ferrara et al. (Leukemia, 2013), including age > 75 years, performance status and comorbidities, were verified retrospectively in 699 patients with AML (419 de-novo, 280 secondary AML), diagnosed at 8 Hematological Centers (REL). Methods: Patients were categorized in FIT to intensive chemotherapy (i-T) (292, 42.5%), UNFIT to i-T (289, 42.1%), or unfit even to non-intensive therapy (non i-T) (FRAIL) (105, 15.3%). Biological characteristics and treatment actually received by patients [i-T, 274 patients (39.2%); non i-T, 134 (19.2%), best-supportive care (BSC), 291 (41.6%)] were recorded. Results: “Fitness criteria” were easily applicable in 98.1% of patients. Overall concordance between “fitness criteria” and treatment actually received by patients was high (79.4%), 76% in FIT, 82.7% in UNFIT and 80% in FRAIL patients. Fitness independently predicted survival (median survival: 10.9, 4.2 and 1.8 months in FIT, UNFIT and FRAIL patients, respectively; p = 0.000), as confirmed also by multivariate analysis. In FRAIL patients, survival with any treatment was no better than with BSC, in UNFIT non i-T was as effective as i-T and better than BSC, and in FIT patients i-T was better than non i-T or BSC. In addition, a non-adverse risk AML, an ECOG PS

Anemia is a frequent manifestation of myelofibrosis (MF) and there is an unmet need for effective treatments in anemic MF patients. The REALISE phase 2 study (NCT02966353) evaluated the efficacy and safety of a novel ruxolitinib dosing strategy with a reduced starting dose with delayed up-titration in anemic MF patients. Fifty-one patients with primary MF (66.7%), post-essential thrombocythemia MF (21.6%), or post-polycythemia vera MF (11.8%) with palpable splenomegaly and hemoglobin

Summary Background Polycythaemia vera is a myeloproliferative neoplasm characterised by excessive proliferation of erythroid, myeloid, and megakaryocytic components in the bone marrow due to mutations in the Janus kinase 2 (JAK2) gene. Ruxolitinib, a JAK 1 and JAK 2 inhibitor, showed superiority over best available therapy in a phase 2 study in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. We aimed to compare the long-term safety and efficacy of ruxolitinib with best available therapy in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. Methods We report the 5-year results for a randomised, open-label, phase 3 study (RESPONSE) that enrolled patients at 109 sites across North America, South America, Europe, and the Asia-Pacific region. Patients (18 years or older) with polycythaemia vera who were resistant to or intolerant of hydroxyurea were randomly assigned 1:1 to receive either ruxolitinib or best available therapy. Patients randomly assigned to the ruxolitinib group received the drug orally at a starting dose of 10 mg twice a day. Single-agent best available therapy comprised hydroxyurea, interferon or pegylated interferon, pipobroman, anagrelide, approved immunomodulators, or observation without pharmacological treatment. The primary endpoint, composite response (patients who achieved both haematocrit control without phlebotomy and 35% or more reduction from baseline in spleen volume) at 32 weeeks was previously reported. Patients receiving best available therapy could cross over to ruxolitinib after week 32. We assessed the durability of primary composite response, complete haematological remission, overall clinicohaematological response, overall survival, patient-reported outcomes, and safety after 5-years of follow-up. This study is registered with ClinicalTrials.gov , NCT01243944 . Findings We enrolled patients between Oct 27, 2010, and Feb 13, 2013, and the study concluded on Feb 9, 2018. Of 342 individuals screened for eligibility, 222 patients were randomly assigned to receive ruxolitinib (n=110, 50%) or best available therapy (n=112, 50%). The median time since polycythaemia vera diagnosis was 8·2 years (IQR 3·9–12·3) in the ruxolitinib group and 9·3 years (4·9–13·8) in the best available therapy group. 98 (88%) of 112 patients initially randomly assigned to best available therapy crossed over to receive ruxolitinib and no patient remained on best available therapy after 80 weeks of study. Among 25 primary responders in the ruxolitinib group, six had progressed at the time of final analysis. At 5 years, the probability of maintaining primary composite response was 74% (95% CI 51–88). The probability of maintaining complete haematological remission was 55% (95% CI 32–73) and the probability of maintaining overall clinicohaematological responses was 67% (54–77). In the intention-to-treat analysis not accounting for crossover, the probability of survival at 5 years was 91·9% (84·4–95·9) with ruxolitinib therapy and 91·0% (82·8–95·4) with best available therapy. Anaemia was the most common adverse event in patients receiving ruxolitinib (rates per 100 patient-years of exposure were 8·9 for ruxolitinib and 8·8 for the crossover population), though most anaemia events were mild to moderate in severity (grade 1 or 2 anaemia rates per 100 patient-years of exposure were 8·0 for ruxolitinib and 8·2 for the crossover population). Non-haematological adverse events were generally lower with long-term ruxolitinib treatment than with best available therapy. Thromboembolic events were lower in the ruxolitinib group than the best available therapy group. There were two on-treatment deaths in the ruxolitinib group. One of these deaths was due to gastric adenocarcinoma, which was assessed by the investigator as related to ruxolitinib treatment. Interpretation We showed that ruxolitinib is a safe and effective long-term treatment option for patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea. Taken together, ruxolitinib treatment offers the first widely approved therapeutic alternative for this post-hydroxyurea patient population. Funding Novartis Pharmaceuticals Corporation.

Lymphoma represents a heterogeneous hematological malignancy (HM), which is characterized by severe immunosuppression. Patients diagnosed of coronavirus disease 2019 (COVID-19) during the course of HM have been described to have poor outcome, with only few reports specifically addressing lymphoma patients. Here, we investigated the clinical behavior and clinical parameters of a large multicenter cohort of adult patients with different lymphoma subtypes, with the aim of identifying predictors of death. The study included 856 patients, of whom 619 were enrolled prospectively in a 1-year frame and were followed-up for a median of 66 days (range 1-395). Patients were managed as outpatient (not-admitted cohort, n = 388) or required hospitalization (n = 468), and median age was 63 years (range 19-94). Overall, the 30- and 100-days mortality was 13% (95% confidence interval (CI), 11% to 15%) and 23% (95% CI, 20% to 27%), respectively. Antilymphoma treatment, including anti-CD20 containing regimens, did not impact survival. Patients with Hodgkin’s lymphoma had the more favorable survival, but this was partly related to significantly younger age. The time interval between lymphoma diagnosis and COVID-19 was inversely related to mortality. Multivariable analysis recognized 4 easy-to-use factors (age, gender, lymphocyte, and platelet count) that were associated with risk of death, both in the admitted and in the not-admitted cohort (HR 3.79 and 8.85 for the intermediate- and high-risk group, respectively). Overall, our study shows that patients should not be deprived of the best available treatment of their underlying disease and indicates which patients are at higher risk of death. This study was registered with ClinicalTrials.gov, NCT04352556.

ROMEI, a prospective, observational study in patients with myelofibrosis receiving the oral JAK1/2 inhibitor ruxolitinib in real-world practice, assesses treatment adherence based on the 8-item Morisky Medication Adherence Scale (MMAS-8). Here, we present MMAS-8 results at week 24. Overall, 101 of 188 evaluable patients completed the questionnaire at every visit (full completers). Mean (±standard deviation) total MMAS-8 scores remained stable from week 4 to week 24 in the overall population (7.54 ± 0.77 and 7.67 ± 0.70, respectively) and full completers (7.53 ± 0.79 and 7.67 ± 0.73, respectively). Rates of low (MMAS-8 ˂6) or medium (MMAS-8 ≥ 6 to ˂8) adherence were 25–40% and 26–36%, respectively. Fifty-five full completers (54%) reported ≥1 change in adherence category (improvement and/or worsening), most of which were associated with unintentional behavior. The data suggest that one-third of patients receiving ruxolitinib may be undertreated due to non-adherence, potentially undermining disease control, and indicate a need for better interventions addressing noncompliance to oral therapies.

Simple Summary Little information has been reported about the impact of the COVID-19 pandemic in Philadelphia-negative chronic myeloproliferative neoplasms (MPN). In this review, we summarize the knowledge about MPN clinical management, including cytoreductive and antiplatelet/anticoagulant therapy, thrombotic risk, prognosis, and vaccination strategies at the time of COVID-19. Abstract An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) started in December 2019 in China and then become pandemic in February 2020. Several publications investigated the possible increased rate of COVID-19 infection in hematological malignancies. Based on the published data, strategies for the management of chronic Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are provided. The risk of severe COVID-19 seems high in MPN, particularly in patients with essential thrombocythemia, but not negligible in myelofibrosis. MPN patients are at high risk of both thrombotic and hemorrhagic complications and this must be accounted in the case of COVID-19 deciding on a case-by-case basis. There are currently no data to suggest that hydroxyurea or interferon may influence the risk or severity of COVID-19 infection. Conversely, while the immunosuppressive activity of ruxolitinib might pose increased risk of infection, its abrupt discontinuation during COVID-19 syndrome is associated with worse outcome. All MPN patients should receive vaccine against COVID-19; reassuring data are available on efficacy of mRNA vaccines in MPNs.

Background PV is a clonal myeloid neoplasm characterized by activating mutations in JAK2 and increased red blood cell production. Reduction of thrombosis risk through lowering of hematocrit (Hct) and thus blood viscosity is critical, but management of constitutional symptoms is also important. HU is an effective and well-tolerated first-line treatment (tx) for PV, but pts who develop resistance to or intolerance of HU have limited tx options. A Phase I study of idasanutlin, an MDM2 antagonist leading to increased p53 activity, showed encouraging efficacy and potential disease-modifying effects via rapid reduction in JAK2 V617F variant allele frequency in 11 pts with PV. These results prompted the larger, international Phase II study of idasanutlin in HU-resistant/intolerant PV (NCT03287245); data from the initial phase of the study are reported here. Methods Pts meeting the 2016 WHO criteria for PV were eligible for inclusion if they had HU-resistant/intolerant disease according to the European LeukemiaNet (ELN) criteria and were phlebotomy dependent (≥ 1 phlebotomy in the 16-wk period prior to screening). Prior PV tx with ruxolitinib (rux) or interferon was allowed. Idasanutlin was given orally once daily on days 1-5 of 28-day cycles for up to 24 mo. The starting dose was 150 mg; increase to 200 mg was allowed for non-responders at cycle 3, day 28, and reduction to 100 mg was permitted for toxicity and for pts treated beyond cycle 12. Antiemetic prophylaxis was mandatory in cycle 1 throughout the study and later became mandatory in all cycles. The primary endpoint (wk 32) was the composite response of Hct control (HTC) and spleen volume reduction > 35% by CT/MRI in pts with splenomegaly (> 450 cm3) and HTC alone in pts without splenomegaly. Key secondary endpoints included safety, complete hematologic response (CHR; defined as HTC and normalization of platelets/leukocytes) and ELN response. Results A total of 27 pts were included in this study and received tx with idasanutlin. Median age was 56 years (range, 34-74) and 16 pts (59.3%) were male (Table 1). All pts had JAK2 V617F mutation; 7 had previous exposure to rux. Median tx duration was 257 days (range, 5-677); the median number of treatment cycles was 8 (range, 1-23). Dose modifications occurred in 17 pts (63.0%; Table 2). A total of 3 serious AEs occurred: atrial flutter, atrial fibrillation and nausea/vomiting (n = 1 each). The serious cardiac AEs occurred in pts with pre-existing hypertension and a past incident of heart failure not symptomatic upon enrollment, respectively. No deaths, transformation to acute myeloid leukemia, progression to myelofibrosis or thrombotic events occurred during the study. AEs occurring in ≥ 15% of pts are listed in Table 3; gastrointestinal toxicity and fatigue were the most common events. The population for primary endpoint evaluation consisted of pts with response assessed at wk 32 (n = 16). One of 13 pts with baseline splenomegaly achieved a composite response (7.7%; Table 4). Nine of 16 pts (56.3%) among all evaluable pts achieved HTC: 6 of 11 rux-naive pts (54.5%) and 3 of 5 rux-exposed pts (60.0%). Eight of 13 pts (61.5%) among all pts had HTC duration ≥ 12 wk beyond wk 32: 5 of 9 rux-naive pts (55.6%) and 3 of 4 rux-exposed pts (75.0%). At wk 32, 8 of 16 pts (50.0%) achieved a CHR, with 6 of 13 (46.2%) having a CHR duration ≥ 12 wk beyond wk 32. Overall response rates per modified ELN response criteria in pts with baseline splenomegaly, pts without baseline splenomegaly and in all pts were 69.2% (9 of 13), 66.7% (2 of 3) and 68.8% (11 of 16), respectively; 9 of 15 pts (60%) among all pts had a response duration ≥ 12 wk beyond wk 32. Median (range) laboratory value changes at wk 32 were: platelets, −253 × 109/L (−2083 to +175) and leukocytes, −4.8 × 109/L (−25.3 to +3.4). At wk 32, 6 of 14 pts (42.9%) had a ≥ 50% reduction in the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score. Conclusions Idasanutlin showed relevant clinical activity in pts with HU-resistant/intolerant PV and also in a subset of pts with prior rux tx. However, the low-grade gastrointestinal toxicity profile of idasanutlin was not effectively mitigated with antiemetic prophylaxis and led to frequent discontinuations. These results iterate the importance of tolerability of novel therapies administered over the long term for pts with PV. Disclosures Mascarenhas: Celgene, Prelude, Galecto, Promedior, Geron, Constellation, and Incyte: Consultancy; Incyte, Kartos, Roche, Promedior, Merck, Merus, Arog, CTI Biopharma, Janssen, and PharmaEssentia: Other: Research funding (institution). Higgins:Roche: Current Employment, Current equity holder in publicly-traded company, Other: Support of parent study and funding of editorial support. Anders:Roche: Current Employment, Other: Support of parent study and funding of editorial support. Burbury:Roche: Other: Support of parent study and funding of editorial support. El-Galaly:F. Hoffmann-La Roche: Current Employment, Other: Support of parent study and funding of editorial support. Gerds:Roche/Genentech: Research Funding; Apexx Oncology: Consultancy; AstraZeneca/MedImmune: Consultancy; Pfizer: Research Funding; Imago Biosciences: Research Funding; Gilead Sciences: Research Funding; Incyte Corporation: Consultancy, Research Funding; Sierra Oncology: Research Funding; CTI Biopharma: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Gupta:Pfizer: Consultancy; Incyte: Honoraria, Research Funding; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kovic:Roche: Other: Support of parent study and funding of editorial support. Maffioli:Roche: Other: Support of parent study and funding of editorial support. Mesa:AbbVie: Research Funding; Sierra Oncology: Consultancy; CTI BioPharma: Research Funding; LaJolla Pharmaceutical Company: Consultancy; Bristol Myers Squibb: Research Funding; Genentech: Research Funding; Samus Therapeutics: Research Funding; Promedior: Research Funding; Novartis: Consultancy; Incyte: Research Funding. Rambaldi:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support of parent study and funding of editorial support. Received travel support., Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Advisory board and speaker fees from Pfizer.; Sanofi: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); BMS/Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); University of Milan: Current Employment; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support from Gilead.; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Omeros: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Astellas: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Research grant from Amgen Inc.. Vannucchi:AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Blueprint: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Yacoub:Roche: Other: Support of parent study and funding of editorial support; Dynavax: Current equity holder in publicly-traded company; Novartis: Speakers Bureau; Agios: Honoraria, Speakers Bureau; Incyte: Speakers Bureau; Hylapharm: Current equity holder in private company; Cara Therapeutics: Current equity holder in publicly-traded company; Ardelyx: Current equity holder in publicly-traded company.

Background Activating mutations in JAK2 are the molecular hallmark of PV. However, achieving molecular remission is not a validated endpoint in PV, as its correlation with patient-relevant endpoints, such as thrombotic events or disease progression, is not well established. The expression of MDM2, a negative regulator of wild-type p53, is significantly higher in CD34+ cells from patients with PV vs those from healthy controls. Therefore, MDM2 antagonists such as idasanutlin (idasa) may have selective and potentially disease-modifying effects in PV. This exploratory analysis reports baseline mutational profiling and serial measurements of JAK2 V617F variant allele frequency (VAF) from patients treated with idasa in the Phase II NP39761 study (NCT03287245). Methods Patients with PV, as defined by the 2016 World Health Organization criteria, were eligible for inclusion if their disease was HU resistant/intolerant according to European LeukemiaNet criteria and they were phlebotomy dependent (≥ 1 phlebotomy in the 16-wk period prior to screening). Prior PV therapy with ruxolitinib and/or interferon was allowed. Idasa was given orally once daily on days 1-5 of 28-day cycles for up to 24 mo. The starting dose was 150 mg, but dose increase (to 200 mg) or decrease (to 100 mg) was allowed per protocol-defined criteria. The primary efficacy endpoints were hematocrit control (HTC), defined as maintaining acceptable hematocrit levels with ≤ 1 phlebotomy between cycle 1, day 1 (C1D1) and wk 8 and no phlebotomy after wk 8, and complete hematologic remission (CHR), defined as HTC together with platelets < 400 × 109/L and white blood cell count < 109/L on the day of response assessment (or most recent test). JAK2 V617F VAF was analyzed at screening and at C3D28, C5D28 and wk 32. The JAK2 V617F VAF was determined using quantitative polymerase chain reaction. Baseline blood samples were sequenced using the Foundation Medicine FoundationOne Heme next-generation sequencing panel, which interrogates > 400 DNA-sequenced genes, to explore the genetic landscape of PV beyond JAK2 V617F. Results All 27 patients enrolled in the study harbored JAK2 V617F. Baseline and ≥ 1 later JAK2 VAF measurements were available in 23 patients, allowing for analysis. The median age was 56 y (range, 34-74), and 7 patients (26%) had been previously treated with ruxolitinib. Median treatment duration was 257 days (range, 5-677), and the median number of treatment cycles was 8 (range, 1-22). JAK2 V617F VAFs at baseline were highly variable, ranging from 7% to 96% (median, 66%). A reduction in JAK2 V617F VAF was observed as early as after 3 cycles (median reduction, 39%; n = 19) and was sustained in patients receiving treatment, with a median reduction of 58% at C5D28 (n = 17) and of 76% at wk 32 (n = 13). The median reductions in JAK2 V617F VAF were significantly higher for patients with CHR and HTC than in nonresponders on C3D28 (CHR, P < 0.01; HTC, P = 0.04) and C5D28 (CHR, P < 0.01; HTC, P = 0.03), with a similar trend also at wk 32 (CHR, P = 0.06; HTC, P = 0.19) (Figures). Baseline targeted sequencing (n = 16) identified several additional subclonal mutations. However, no TP53 mutations were detected. Variants in TET2 and ASXL1 were detected in 37% (6 of 16) and 20% (3 of 16) of patients, with VAFs of 2%-51% and 38%-50%, respectively. Notably, 68% of the patients had variants detected in 1 to 3 DNA repair genes, including ATM (VAF, 47%-52%), ATR (VAF, 49%), BRCA2 (VAF, 47%-51%), PARP1 (VAF, 52%), PARP3 (VAF, 48%), FANCM (VAF, 47%-50%), BLM (VAF, 48%) and MSH3 (VAF, 49%). In the absence of sequencing of patient-matched non-hematologic tissue and the VAFs being ≈50%, it is possible some of these variants are germline. Whether such variants predispose to PV is unknown. Conclusions Idasa has relevant clinical activity in patients with PV who are resistant to or intolerant of HU and showed rapid JAK2 V617F VAF reduction in a subset of patients as early as after 3 treatment cycles. The median JAK2 VAF reduction was significantly greater in patients who achieved CHR and HTC after 3 and 5 cycles of idasa treatment, suggesting that early molecular response was associated with higher likelihood of clinical response. Baseline mutations were seen in several genes commonly mutated in PV. A high frequency of variants in DNA repair genes has not previously been reported in PV and may contribute to genomic instability in this disease. Figure Disclosures Passamonti: Roche: Other: Support of parent study and funding of editorial support; BMS: Speakers Bureau; Novartis: Speakers Bureau. El-Galaly:F. Hoffmann-La Roche: Current Employment, Other: Support of parent study and funding of editorial support. Gerds:Celgene: Consultancy, Research Funding; Gilead Sciences: Research Funding; CTI Biopharma: Consultancy, Research Funding; Imago Biosciences: Research Funding; AstraZeneca/MedImmune: Consultancy; Roche/Genentech: Research Funding; Incyte Corporation: Consultancy, Research Funding; Pfizer: Research Funding; Apexx Oncology: Consultancy; Sierra Oncology: Research Funding. Gupta:Incyte: Honoraria, Research Funding; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy. Higgins:Roche: Current Employment, Current equity holder in publicly-traded company, Other: Support of parent study and funding of editorial support. Huw:Roche: Current Employment, Other: Support of parent study and funding of editorial support. Maffioli:Roche: Other: Support of parent study and funding of editorial support. Mesa:Sierra Oncology: Consultancy; Incyte: Research Funding; Samus Therapeutics: Research Funding; Promedior: Research Funding; Genentech: Research Funding; Novartis: Consultancy; CTI BioPharma: Research Funding; LaJolla Pharmaceutical Company: Consultancy; AbbVie: Research Funding; Bristol Myers Squibb: Research Funding. Rambaldi:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support of parent study and funding of editorial support. Received travel support., Research Funding; Sanofi: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Astellas: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support from Gilead.; BMS/Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Advisory board and speaker fees from Pfizer.; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Research grant from Amgen Inc.; Omeros: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); University of Milan: Current Employment. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Blueprint: Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Yacoub:Incyte: Speakers Bureau; Hylapharm: Current equity holder in private company; Cara Therapeutics: Current equity holder in publicly-traded company; Dynavax: Current equity holder in publicly-traded company; Agios: Honoraria, Speakers Bureau; Novartis: Speakers Bureau; Roche: Other: Support of parent study and funding of editorial support; Ardelyx: Current equity holder in publicly-traded company. Mascarenhas:Celgene, Prelude, Galecto, Promedior, Geron, Constellation, and Incyte: Consultancy; Incyte, Kartos, Roche, Promedior, Merck, Merus, Arog, CTI Biopharma, Janssen, and PharmaEssentia: Other: Research funding (institution).

PURPOSE Recurrently mutated genes and chromosomal abnormalities have been identified in myelodysplastic syndromes (MDS). We aim to integrate these genomic features into disease classification and prognostication. METHODS We retrospectively enrolled 2,043 patients. Using Bayesian networks and Dirichlet processes, we combined mutations in 47 genes with cytogenetic abnormalities to identify genetic associations and subgroups. Random-effects Cox proportional hazards multistate modeling was used for developing prognostic models. An independent validation on 318 cases was performed. RESULTS We identify eight MDS groups (clusters) according to specific genomic features. In five groups, dominant genomic features include splicing gene mutations ( SF3B1, SRSF2, and U2AF1) that occur early in disease history, determine specific phenotypes, and drive disease evolution. These groups display different prognosis (groups with SF3B1 mutations being associated with better survival). Specific co-mutation patterns account for clinical heterogeneity within SF3B1- and SRSF2-related MDS. MDS with complex karyotype and/or TP53 gene abnormalities and MDS with acute leukemia–like mutations show poorest prognosis. MDS with 5q deletion are clustered into two distinct groups according to the number of mutated genes and/or presence of TP53 mutations. By integrating 63 clinical and genomic variables, we define a novel prognostic model that generates personally tailored predictions of survival. The predicted and observed outcomes correlate well in internal cross-validation and in an independent external cohort. This model substantially improves predictive accuracy of currently available prognostic tools. We have created a Web portal that allows outcome predictions to be generated for user-defined constellations of genomic and clinical features. CONCLUSION Genomic landscape in MDS reveals distinct subgroups associated with specific clinical features and discrete patterns of evolution, providing a proof of concept for next-generation disease classification and prognosis.

Introduction: Randomized clinical trials showed that bortezomib, in addition to conventional chemotherapy, improves survival and disease progression in multiple myeloma (MM) patients not eligible for stem cell transplantation. The aim of this retrospective population-based cohort study is the evaluation of both clinical and economic profile of bortezomib-based versus conventional chemotherapy in daily clinical practice. Methods: Healthcare utilization databases of six Italian regions were used to identify adult patients with non-transplant MM, who started a first-line therapy with bortezomib-based or conventional chemotherapy. Patients were matched by propensity score and were followed from treatment start until death, lost to follow-up or study end-point. Overall survival (OS) and restricted mean survival time (RMST) were estimated using the Kaplan–Meier method. Association between first-line treatment and risk of death was estimated by a conditional Cox proportional regression model. Average mean cumulative costs were estimated and compared between groups. Results: In the period 2010–2016, 3509 non-transplant MM patients met the inclusion criteria, of which 1157 treated with bortezomib-based therapy were matched to 1826 treated with conventional chemotherapy. Median OS and RMST were 33.9 and 27.9 months, and 42.9 and 38.4 months, respectively, in the two treatment arms. Overall, these values corresponded to a HR of death of 0.79 (95% CI 0.71–0.89) over a time horizon of 84 months. Average cumulative cost were 83,839 € and 54,499 €, respectively, corresponding to an incremental cost-effectiveness ratio of 54,333 € per year of life gained, a cost coherent with the willingness-to-pay thresholds frequently adopted from Western countries. Conclusions: These data suggested that, in a large cohort of non-transplant MM patients treated outside the experimental setting, first-line treatment with bortezomib-based therapy was associated with a favourable effectiveness and cost-effectiveness profile.

Context: Ibrutinib inhibits BTK with the most typical response in CLL being partial remission (PR) with measurable minimal residual disease (MRD) in blood. Remission is usually maintained until development of genetically-driven resistance. Objective: Mechanism of adaptation and survival in MRD. Patients and Methods: Pre-treatment CLL cells and under-treatment MRD were systematically collected from 33 high-risk CLL patients. Samples were characterized by high-dimensional, single-cell flow cytometry; bulk genomic, transcriptomic, and chromatin accessibility profiling; and single-cell RNA-seq profiling. Results: The genetic composition of MRD remained constant across timepoints, indicating that ibrutinib did not have any impact in shaping its genomic diversity. Ibrutinib induced chromatin dynamics in MRD resulting in a predominantly closed state. Chromatin regions that became more accessible under ibrutinib were enriched of binding sites for transcription factor that lay downstream ERK signaling. Regions that turned into a less accessible state were enriched for the binding sites of TF emanating from the BCR. At the transcriptomic level, most of the differentially expressed genes between pre- and post-treatment samples were downregulated in MRD, while only a fraction was upregulated. IL4, NF-kB, and metabolism and proliferation signatures were downregulated in MRD, while MAPK and RAS signatures were upregulated. CLL spleen samples from TCL1 mice under ibrutinib treatment showed an upregulation of MAPK pathway genes compared to untreated mice. Single-cell transcriptomes revealed a distinct post-treatment cell population driven by MAPK activity that functionally pre-existed in a fraction of CLL cells of baseline samples before ibrutinib start. At the signaling level, ibrutinib had no effect on the integrity of RAS-BRAF-MAPK-ERK pathway protein expression upon crosslinking of the BCR with anti-IgM but not after stimulation of TLR9 or CD40. Functional validation on primary samples by western blotting shows that RAS/ERK can be activated by BCR stimulation, irrespective of ibrutinib treatment in ex vivo experiments. Pharmacological inhibition of MEK (trametinib) and ERK (ulixertinib) synergized with ibrutinib, leading to decreased cell viability. Conclusions: MRD under ibrutinib adapts its phenotype in an epigenetic way to maintain functional competence of BCR signaling via the MAPK pathway, which turned to be a vulnerability of MRD persisting under ibrutinib.

Myelofibrosis symptoms compromise health-related quality of life (HRQoL). Ruxolitinib can reduce myelofibrosis symptom severity, but many patients discontinue ruxolitinib due to loss of response or unacceptable toxicity. Fedratinib is an oral, selective JAK2 inhibitor approved in the United States for treatment of patients with intermediate-2 or high-risk myelofibrosis. The single-arm, phase II JAKARTA2 trial assessed fedratinib 400 mg/d (starting dose) in patients with myelofibrosis previously treated with ruxolitinib. Patient-reported changes in myelofibrosis symptom severity using the modified Myelofibrosis Symptom Assessment Form (MFSAF), and overall HRQoL and functional status using the EORTC QLQ-C30, were evaluated at each cycle. Clinically meaningful changes from baseline HRQoL scores were based on effect sizes. Ninety patients were MFSAF-evaluable. Myelofibrosis symptoms were mild-to-moderate at baseline. Patients showed statistically significant and clinically meaningful improvements in total symptom scores from baseline on the MFSAF at all post baseline visits through the end of cycle 6 (EOC6). Baseline global health status/QoL and functional domain scores on the EORTC QLQ-C30 were meaningfully worse than in the general population. At EOC6, 44% of patients reported clinically meaningful improvements in global health status/QoL, and 30%-53% of patients experienced clinically meaningful improvement in QLQ-C30 functional domains across post baseline timepoints. Over 80% of ongoing patients perceived fedratinib as beneficial on the Patient's Global Impression of Change questionnaire. Fedratinib effects were consistent among prognostically relevant patient subgroups. Patients with myelofibrosis previously treated with ruxolitinib experienced clinically meaningful improvements in myelofibrosis symptom burden, overall HRQoL, and functional status in the first 6 months of fedratinib treatment.

Patients with myelofibrosis (MF) experience an array of symptoms that impair health-related quality of life (HRQoL). Fedratinib, an oral, selective Janus-kinase 2 (JAK2) inhibitor, was investigated in the randomized, placebo-controlled, phase III JAKARTA study in adult patients with intermediate- or high-risk JAK-inhibitor-naïve MF. The effect of fedratinib 400 mg/d on patient-reported MF symptoms and HRQoL in JAKARTA was assessed. Participants completed the modified Myelofibrosis Symptom Assessment Form (MFSAF v2.0), which evaluates 6 key MF symptoms (night sweats, early satiety, pruritus, pain under ribs on the left side, abdominal discomfort, bone/muscle pain). The modified MFSAF v2.0 was completed during the first 6 treatment cycles and at end of cycle 6 (EOC6). Symptom response was a ≥50% improvement from baseline in total symptom score (TSS). Overall HRQoL was assessed by EQ-5D-3L health utility index (HUI) score. The MFSAF-evaluable population comprised 91/96 patients randomized to fedratinib 400 mg and 85/96 patients randomized to placebo. Mean baseline TSS was 17.6 and 14.7 for fedratinib and placebo, respectively, and mean EQ-5D-3L HUI was 0.70 and 0.72. Fedratinib elicited statistically significant and clinically meaningful improvements in TSS from baseline versus placebo at all postbaseline visits. Symptom response rates at EOC6 were 40.4% with fedratinib and 8.6% with placebo (OR 7.0 [95% CI, 2.9-16.9]; P < 0.001), and a significantly higher proportion of fedratinib-treated patients achieved clinically meaningful improvement from baseline on the EQ-5D-3L HUI at EOC6 (23.2% versus 6.5%; P = 0.002). Fedratinib provided clinically meaningful improvements in MF symptoms and overall HRQoL versus placebo in patients with JAK-inhibitor-naïve MF.

Background: Vaccines against SARS-CoV-2 have shown remarkable efficacy and thus constitute an important preventive option against COVID-19, especially in fragile patients. We aimed to systematically analyse the outcomes of patients with haematological malignancies who received COVID-19 vaccination and to identify specific groups with differences in outcomes. Methods: We developed a living systematic review and meta-analysis of published studies that reported data on the outcomes of adult patients with haematological malignancies that received COVID-19 vaccination, reported between July 1, 2020, and September 15, 2021. Studies with ten patients or fewer were excluded and summary data were extracted from the reports. The primary end point was the number of patients with antibody response after full vaccination. This study is registered with PROSPERO (CRD42021279051). Findings: We identified 43 studies comprising 10416 patients. Overall risk of bias was low. The pooled response for haematological malignancies was 65% (95% confidence interval [CI], 60-70; I²=93%) compared with 95% (95% CI, 92-97; I²=27%) for solid cancer and 98% (95% CI, 96-99; I² =60%) for healthy controls (P

In this issue of Leukemia & Lymphoma Wagner-Johnston et al. [1] reported an intriguing post-hoc analysis of three registrational trials of idelalisib in indolent non-Hodgkin lymphoma (iNHL) and chr...

Ruxolitinib, a potent Janus kinase 1/2 inhibitor, has demonstrated durable improvements in patients with myelofibrosis. In this analysis of the Phase 3b JUMP study, which included patients aged ≥18 years with a diagnosis of primary or secondary myelofibrosis, we assessed the safety and efficacy of ruxolitinib in patients stratified by Dynamic International Prognostic Scoring System (DIPSS) risk categories. Baseline characteristic data were available to assess DIPSS status for 1844 of the 2233 enrolled patients; 60, 835, 755, and 194 in the low‐, intermediate (Int)‐1‐, Int‐2‐, and high‐risk groups, respectively. Ruxolitinib was generally well tolerated across all risk groups, with an adverse‐event (AE) profile consistent with previous reports. The most common hematologic AEs were thrombocytopenia and anemia, with highest rates of Grade ≥3 events in high‐risk patients. Approximately, 73% of patients experienced ≥50% reductions in palpable spleen length at any point in the ≤24‐month treatment period, with highest rates in lower‐risk categories (low, 82.1%; Int‐1, 79.3%; Int‐2, 67.1%; high risk, 61.6%). Median time to spleen length reduction was 5.1 weeks and was shortest in lower‐risk patients. Across measures, 40%–57% of patients showed clinically meaningful symptom improvements, which were observed from 4 weeks after treatment initiation and maintained throughout the study. Overall survival (OS) was 92% at Week 72 and 75% at Week 240 (4.6 years). Median OS was longer for Int‐2‐risk than high‐risk patients (253.6 vs. 147.3 weeks), but not evaluable in low‐/Int‐1‐risk patients. By Week 240, progression‐free survival (PFS) and leukemia‐free survival (LFS) rates were higher in lower‐risk patients (PFS: low, 90%; Int‐1, 82%; Int‐2, 46%; high risk, 15%; LFS: low, 92%; Int‐1, 86%; Int‐2, 58%; high risk, 19%). Clinical benefit was seen across risk groups, with more rapid improvements in lower risk patients. Overall, this analysis indicates that ruxolitinib benefits lower‐risk DIPSS patients in addition to higher risk.

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

Clonal hematopoiesis of indeterminate potential (CHIP) is associated with increased risk of cancers and inflammation-related diseases. This phenomenon becomes common in persons aged ≥80 years, in whom the implications of CHIP are not well defined. We performed a mutational screening in 1794 persons aged ≥80 years and investigated the relationships between CHIP and associated pathologies. Mutations were observed in one-third of persons aged ≥80 years and were associated with reduced survival. Mutations in JAK2 and splicing genes, multiple mutations (DNMT3A, TET2, and ASXL1 with additional genetic lesions), and variant allele frequency ≥0.096 had positive predictive value for myeloid neoplasms. Combining mutation profiles with abnormalities in red blood cell indices improved the ability of myeloid neoplasm prediction. On this basis, we defined a predictive model that identifies 3 risk groups with different probabilities of developing myeloid neoplasms. Mutations in DNMT3A, TET2, ASXL1, or JAK2 were associated with coronary heart disease and rheumatoid arthritis. Cytopenia was common in persons aged ≥80 years, with the underlying cause remaining unexplained in 30% of cases. Among individuals with unexplained cytopenia, the presence of highly specific mutation patterns was associated with myelodysplastic-like phenotype and a probability of survival comparable to that of myeloid neoplasms. Accordingly, 7.5% of subjects aged ≥80 years with cytopenia had presumptive evidence of myeloid neoplasm. In summary, specific mutational patterns define different risk of developing myeloid neoplasms vs inflammatory-associated diseases in persons aged ≥80 years. In individuals with unexplained cytopenia, mutational status may identify those subjects with presumptive evidence of myeloid neoplasms.

COVID-19 is associated with high mortality in patients with haematological malignancies (HM) and rate of seroconversion is unknown. The ITA-HEMA-COV project (NCT04352556) investigated patterns of seroconversion for SARS-CoV-2 IgG in patients with HMs. A total of 237 patients, SARS-CoV-2 PCR-positive with at least one SARS-CoV-2 IgG test performed during their care, entered the analysis. Among these, 62 (26·2%) had myeloid, 121 (51·1%) lymphoid and 54 (22·8%) plasma cell neoplasms. Overall, 69% of patients (164 of 237) had detectable IgG SARS-CoV-2 serum antibodies. Serologically negative patients (31%, 73 of 237) were evenly distributed across patients with myeloid, lymphoid and plasma cell neoplasms. In the multivariable logistic regression, chemoimmunotherapy [odds ratio (OR), 3·42; 95% confidence interval (CI), 1·04–11·21; P=0·04] was associated with a lower rate of seroconversion. This effect did not decline after 180days from treatment withdrawal (OR, 0·35; 95% CI: 0·11–1·13; P=0·08). This study demonstrates a low rate of seroconversion in HM patients and indicates that treatment-mediated immune dysfunction is the main driver. As a consequence, we expect a low rate of seroconversion after vaccination and thus we suggest testing the efficacy of seroconversion in HM patients.

Contains fulltext : 220650.pdf (Publisher’s version ) (Open Access) Fedratinib is an oral, selective Janus kinase 2 (JAK2) inhibitor. The phase II JAKARTA2 study assessed fedratinib in patients with intermediate- or high-risk myelofibrosis (MF) who were resistant or intolerant to prior ruxolitinib per investigator assessment. Patients received fedratinib 400 mg/day in 28-day cycles. The JAKARTA2 outcomes were initially reported using a last-observation-carried forward (LOCF) analysis in a "Per Protocol" population. This updated analysis of JAKARTA2 employs intention-to-treat analysis principles without LOCF for all treated patients (ITT Population; N = 97), and for a patient subgroup who met more stringent definitions of prior ruxolitinib failure (Stringent Criteria Cohort; n = 79). Median duration of prior ruxolitinib exposure was 10.7 months. The primary endpoint was spleen volume response rate (SVRR; >/=35% spleen volume decrease from baseline to end of cycle 6 [EOC6]). The SVRR was 31% in the ITT Population and 30% in the Stringent Criteria Cohort. Median duration of spleen volume response was not reached. Symptom response rate (>/=50% reduction from baseline to EOC6 in total symptom score [TSS] on the modified Myelofibrosis Symptom Assessment Form [MFSAF]) was 27%. Grade 3-4 anemia and thrombocytopenia rates were 38% and 22%, respectively. Patients with advanced MF substantially pretreated with ruxolitinib attained robust spleen responses and reduced symptom burden with fedratinib.

Myeloproliferative neoplasms (MPNs) are the most frequent underlying causes of splanchnic vein thromboses (SVTs). MPN patients with SVTs (MPN-SVT) often have a unique presentation including younger age, female predominance, and low Janus kinase 2 (JAK2) mutation allele burden. This study aimed at identifying risk factors for adverse hematologic outcomes in MPN-SVT patients. We performed a retrospective study of a fully characterized cohort of MPN-SVT patients. The primary outcome was the incidence of evolution to myelofibrosis, acute leukemia, or death. Eighty patients were included in the testing cohort. Median follow-up was 11 years. Most of the patients were women with a mean age of 42 years and a diagnosis of polycythemia vera. The primary outcome was met in 13% of the patients and was associated with a JAK2V617F allele burden ≥50% (odds ratio [OR], 14.7) and presence of additional mutations in genes affecting chromatin/spliceosome (OR, 9). We identified high-risk patients (29% of the cohort) as those harboring at least 1 molecular risk factor: JAK2-mutant allele burden ≥50%, presence of chromatin/spliceosome/TP53 mutation. High-risk patients had worse event-free survival (81% vs 100%; P = .001) and overall survival at 10 years (89% vs 100%; P = .01) than low-risk patients. These results were confirmed in an independent validation cohort of 30 MPN-SVT patients. In conclusion, molecular profiling identified MPN-SVT patients with dismal outcome. In this high-risk population, a disease-modifying therapy should be taken into consideration to minimize the probability of transformation.

Recent studies have demonstrated feasibility and substantial benefit of direct-acting antivirals (DAAs) administration during or after first-line immune-chemotherapy (I-CT) in patients with hepatitis C virus (HCV)-positive diffuse large B-cell lymphomas (DLBCL). However, data on DAAs used during or after salvage treatments are still lacking. In this study we assessed clinical and virological outcome in 11 patients with relapsed (

This review focuses on the management of elderly patients with chronic myeloid leukemia and chronic myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia and primary myelofibrosis. Median age in these neoplasms is within the 6th decades of age. All new therapies can be done at any age without absolute contraindication. However, the selection of the precise therapy for the single patient is mandatory. For these reasons, an accurate definition of diagnosis and prognostication is necessary. Precision in disease definition and prognostication is definitively helpful for personalizing therapeutic approach.

Background The JAK inhibitor (JAKi) ruxolitinib is standard treatment for myelofibrosis (MF), but some patients are unresponsive. Pre-clinical and clinical data suggest that addition of a Hedgehog pathway inhibitor (HPI) to ruxolitinib might improve response. Vismodegib is an HPI approved for treatment of locally advanced and metastatic basal cell carcinoma. The MYLIE study assessed the safety and efficacy of combining ruxolitinib with vismodegib in ruxolitinib-naive patients with MF and characterized the pharmacokinetics (PK) of vismodegib in this setting. Methods In this phase Ib study, ten patients with intermediate- or high-risk primary or secondary MF received open-label vismodegib (150 mg/day orally) and ruxolitinib (15 or 20 mg orally twice daily, depending on baseline platelet count) for up to 48 weeks, or until withdrawal or discontinuation. PK samples were collected throughout the study for comparison with other patient populations. Efficacy outcomes at week 24 included spleen response (≥ 35% reduction in volume by imaging) and improvement in bone marrow fibrosis by central and investigator assessment, symptom response (≥ 50% reduction in Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom score), and anemia response (per International Working Group for Myeloproliferative Neoplasms Research and Treatment revised response criteria). Results As of November 17, 2017, eight patients had completed 48 weeks of treatment with vismodegib and ruxolitinib; two discontinued treatment early. At week 24 (± 1 week), three patients experienced a spleen response by central review and no patients showed a 1-grade improvement in bone marrow fibrosis by central review. Five patients experienced symptom response at week 24, and no patients experienced an anemia response. The most common adverse events were muscle spasm (100% of patients), alopecia (70%), dysgeusia (50%), thrombocytopenia (50%), and nausea (40%); these events were predominantly grade 1/2. Three patients experienced a total of six serious adverse events. Conclusions The combination of vismodegib and ruxolitinib was tolerable and no new safety signals were seen, but there was no evidence that the addition of vismodegib to ruxolitinib improved any of the efficacy outcome measures assessed. Further evaluation of this combination will not be pursued. Trial registration ClinicalTrials.gov, NCT02593760. Registered November 2, 2015.

SETBP1 variants occur as somatic mutations in several hematological malignancies such as atypical chronic myeloid leukemia and as de novo germline mutations in the Schinzel–Giedion syndrome. Here we show that SETBP1 binds to gDNA in AT-rich promoter regions, causing activation of gene expression through recruitment of a HCF1/KMT2A/PHF8 epigenetic complex. Deletion of two AT-hooks abrogates the binding of SETBP1 to gDNA and impairs target gene upregulation. Genes controlled by SETBP1 such as MECOM are significantly upregulated in leukemias containing SETBP1 mutations. Gene ontology analysis of deregulated SETBP1 target genes indicates that they are also key controllers of visceral organ development and brain morphogenesis. In line with these findings, in utero brain electroporation of mutated SETBP1 causes impairment of mouse neurogenesis with a profound delay in neuronal migration. In summary, this work unveils a SETBP1 function that directly affects gene transcription and clarifies the mechanism operating in myeloid malignancies and in the Schinzel–Giedion syndrome caused by SETBP1 mutations., SETBP1 variants occur as somatic mutations in several malignancies and as de novo germline mutations in developmental disorders. Here the authors provide evidence that SETBP1 binds to gDNA in AT-rich promoter regions to promote target gene upregulation, indicating SETBP1 functions directly to regulate transcription.

WOS: 000426644800007, PubMed ID: 29396713, Ruxolitinib was well tolerated and superior to best available therapy (including interferon [IFN]) in controlling hematocrit without phlebotomy eligibility, normalizing blood counts, and improving polycythemia vera-related symptoms in the Study of Efficacy and Safety in Polycythemia Vera Subjects Who Are Resistant to or Intolerant of Hydroxyurea: JAK Inhibitor INC424 (INCB018424) Tablets Versus Best Available Care (RESPONSE) studies. This ad hoc analysis focuses on ruxolitinib in relation to IFN in the RESPONSE studies, with attention on the following: (1) safety and efficacy of ruxolitinib and best available therapy in patients who received IFN before study randomization, (2) safety and efficacy of IFN during randomized treatment in best available therapy arm, and (3) use of ruxolitinib after crossover from best available therapy in IFN-treated patients. IFN exposure before randomization had little effect on the efficacy or safety of ruxolitinib. In the randomized treatment arms, ruxolitinib was superior to IFN in efficacy [hematocrit control (RESPONSE = 60% of ruxolitinib vs 23% of IFN patients; RESPONSE-2 = 62% of ruxolitinib vs 15% of IFN patients)] and was tolerated better in hydroxyurea-resistant or hydroxyurea-intolerant patients. After crossing over to receive ruxolitinib, patients who had initially received IFN and did not respond had improved hematologic and spleen responses (62% of patients at any time after crossover) and an overall reduction in phlebotomy procedures. Rates and incidences of the most common adverse events decreased after crossover to ruxolitinib, except for infections (primarily grade 1 or 2). These data suggest that ruxolitinib is efficacious and well tolerated in patients who were previously treated with IFN. The RESPONSE (NCT01243944) and RESPONSE-2 (NCT02038036) studies were registered at clinicaltrials.gov., Novartis (CH); Novartis Pharmaceuticals Corporation (US) [Not applicable]

Purpose To develop a prognostic system for transplantation-age patients with primary myelofibrosis (PMF) that integrates clinical, cytogenetic, and mutation data. Patients and Methods The study included 805 patients with PMF age ≤ 70 years recruited from multiple Italian centers and the Mayo Clinic (Rochester, MN), forming two independent learning and validation cohorts. A Cox multivariable model was used to select from among a list of 22 variables those that were predictive of overall survival (OS). Integrated clinical and genetic prognostic models with (MIPSS70-plus) or without (MIPSS70) cytogenetic information were developed. Results Multivariable analysis identified the following as significant risk factors for OS: hemoglobin < 100 g/L, leukocytes > 25 × 109/L, platelets < 100 × 109/L, circulating blasts ≥ 2%, bone marrow fibrosis grade ≥ 2, constitutional symptoms, absence of CALR type-1 mutation, presence of high–molecular risk mutation (ie, ASXL1, EZH2, SRSF2, IDH1/ 2), and presence of two or more high–molecular risk mutations. By assigning hazard ratio (HR)–weighted points to these variables, three risk categories were delineated for the MIPSS70 model; 5-year OS was 95% in low-risk, 70% in intermediate-risk, and 29% in high-risk categories, corresponding to median OS of 27.7 years (95% CI, 22 to 34 years), 7.1 years (95% CI, 6.2 to 8.1 years), and 2.3 years (95% CI, 1.9 to 2.7 years), respectively. In the MIPSS70-plus model, which included cytogenetic information, four risk categories were delineated, with 5-year OS of 91% in low-risk, 66% in intermediate-risk (HR, 3.2; 95% CI, 1.9 to 5.2), 42% in high-risk (HR, 6.4; 95% CI, 4.1 to 10.0), and 7% very high–risk categories (HR, 17.0; 95% CI, 9.8 to 29.2). Both models remained effective after inclusion of older patients in the analysis. Conclusion MIPSS70 and MIPSS70-plus provide complementary systems of risk stratification for transplantation-age patients with PMF and integrate prognostically relevant clinical, cytogenetic, and mutation data.

A total of 410 patients with blast phase myeloproliferative neoplasm (MPN-BP) were retrospectively reviewed: 248 from the Mayo Clinic and 162 from Italy. Median survival was 3.6 months, with no improvement over the last 15 years. Multivariable analysis performed on the Mayo cohort identified high risk karyotype, platelet count 65 years and transfusion need as independent risk factors for survival. Also in the Mayo cohort, intensive chemotherapy resulted in complete remission (CR) or CR with incomplete count recovery (CRi) rates of 35 and 24%, respectively; treatment-specified 3-year/5-year survival rates were 32/10% for patients receiving allogeneic stem cell transplant (AlloSCT) (n = 24), 19/13% for patients achieving CR/CRi but were not transplanted (n = 24), and 1/1% in the absence of both AlloSCT and CR/CRi (n = 200) (p

In this issue of Blood, Gagelmann et al1 describe an integrated clinical-molecular prognostic model (Myelofibrosis Transplant Scoring System [MTSS]) to predict outcome post stem cell transplant (SCT) in myelofibrosis (MF). MF is a clonal stem cell neoplasm with heterogeneous clinical phenotypes and well-defined driver mutations found in ∼90% of the cases.2 Despite the introduction of JAK inhibitors,3 MF still remains an incurable disease with a median survival of 4 to 5 years. SCT is an option for MF patients,4 but, because of the very high risk of mortality, the patient selection is very critical.

Introduction: Cytoreductive therapy such as hydroxyurea and interferon is recommended for high-risk polycythemia vera (PV) patients (pts) and is often used as first-line (1L) therapy. Yet, nearly a quarter of pts discontinue 1L therapy due to resistance or intolerance, requiring second-line (2L) therapy. While ruxolitinib (RUX) is an FDA- and EMA-approved agent for treating resistant or intolerant PV, many pts continue 1L therapy in real-world clinical practice. With a primary objective to assess the event-free survival (EFS) of RUX as 2L therapy in high-risk PV pts ("switchers") relative to pts who stay on 1L therapy ("non-switchers") after suboptimal response, we initiated a multinational, retrospective chart review study with a recruitment target of 350 pts across 25 clinical sites in 9 countries. This study is the first of its kind; the current analysis describes the characteristics of an interim sample of RUX switchers and non-switchers following suboptimal response to 1L therapy. Methods: The analysis included an interim sample of eligible pts with data extracted from medical charts from Feb 2020-Jun 2021. Pt eligibility included those ≥18 years old with JAK2 positive PV diagnosed in 2012 or later and a high-risk constellation, suboptimal response to 1L therapy (criteria in Table 1) after ≥12 months of treatment, and ≥6 months of follow-up after suboptimal response except in the event of death. Pts were excluded if they initiated PV treatment other than RUX after suboptimal response. Pts were classified into switchers vs non-switchers based on whether they switched to RUX following first suboptimal response (i.e., index date). Descriptive statistics were used to summarize criteria for suboptimal response, pt characteristics and comorbidities at any time prior to the index date, and PV-related symptoms 12 months prior to the index date (i.e., baseline period). Analyses were conducted separately for switchers and non-switchers. Results: In the interim sample of 137 pts, 44 (32.1%) were classified as switchers and 93 (67.9%) as non-switchers. Switchers tended to be younger at PV diagnosis than non-switchers (mean [SD]: 66.5 [12.0] vs 70.2 [8.5] years) and were more likely to be male (52.3% vs 47.3%). Median (interquartile range) time from PV diagnosis to index date was shorter for switchers than non-switchers (13.6 [12.3-22.3] vs 20.6 [14.7-37.0] months). Distribution of suboptimal response criteria differed for the two groups: "persistence of PV-related symptoms or presence of new PV-related symptoms" was the most common criterion for switchers, reported in 47.7% of pts vs 15.1% of non-switchers, while "the need for ≥3 phlebotomies to maintain hematocrit More switchers (54.4%) than non-switchers (31.2%) had a history of thrombosis at time of PV diagnosis. Commonly reported comorbidities included hypertension (43.2% switchers vs 66.7% non-switchers), cardiac conditions (18.2% vs 29.0%), hypercholesterolemia (9.1% vs 25.8%), and diabetes (2.3% vs 16.1%) and tended to be less prevalent in switchers than non-switchers. The most observed PV-related symptoms in the baseline period for both groups were fatigue (18.2% switchers vs 16.1% non-switchers) and pruritus (15.9% vs 14.0%). Fewer switchers (36.4%) than non-switchers (60.2%) received phlebotomies in the baseline period while the mean (SD) number of procedures was similar (3.8 [2.3] vs 3.9 [2.8]). Spleen size assessment by palpation was available in 13 switchers (29.5%) and 38 non-switchers (40.9%) on index date, with switchers tending to have a lower proportion of normal size (18.2% vs 37.6%) and a higher proportion of mild or moderate splenomegaly (11.4% vs 3.3%). Conclusions: This analysis shows the trending existence of clinical differences between switchers and non-switchers, with a milder comorbidity profile in switchers. Moreover, while switchers experienced similar PV-related symptoms relative to non-switchers at baseline, switchers were more likely to experience persistence of PV-related symptoms or presence of new symptoms as their suboptimal response type. Taken together, these two factors may have influenced clinicians' decisions to switch to RUX or continue 1L therapy. Upon completion, this novel study will examine the potential impact of switching vs non-switching on EFS in this population. Figure 1 Figure 1. Disclosures Koschmieder: Alexion: Other: Travel support; Geron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Roche: 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, Other: (e.g. travel support); Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); AOP Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Shire: Honoraria, Other; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Karthos: Other: Travel support; Abbvie: Other: Travel support; Baxalta: Membership on an entity's Board of Directors or advisory committees, Other; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; CTI: Membership on an entity's Board of Directors or advisory committees, Other; Image Biosciences: Other: Travel support. Schulte: Novartis: Consultancy. von der Heyde: BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees; Ipsen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Busque: Novartis: Consultancy. Boyer-Perrard: Novartis: Consultancy. Devos: Alexion, AstraZeneca Rare Disease Inc.: Consultancy; Novartis: Consultancy; AbbVie: Consultancy; Incyte: Consultancy; Bristol Myers Squibb - Celegene: Consultancy. Passamonti: 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; 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. Zuurman: Novartis: Current Employment. Paley: Novartis: Ended employment in the past 24 months. Gilotti: Novartis: Current Employment. Cheng: Novartis: Other: I am an employee of Analysis Group, a consulting company that received funding from Novartis for this research study.. Gao: Novartis: Other: I am an employee of Analysis Group, a consulting company that received funding from Novartis for this research study.. Cheng: Novartis: Other: I am an employee of Analysis Group, a consulting company that received funding from Novartis for this research study.. Wu: Novartis: Other: I am an employee of Analysis Group, a consulting company that received funding from Novartis for this research study. Duh: Novartis: Other: I am an employee of Analysis Group, a consulting company that received funding from Novartis for this research study.. Harrison: Incyte Corporation: Speakers Bureau; Geron: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Keros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Promedior: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Constellation Pharmaceuticals: Research Funding; Sierra Oncology: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Galacteo: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: 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, Speakers Bureau; AOP Orphan Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Introduction: Myelofibrosis (MF) is a rare myeloproliferative disorder in whichdysregulation of the janus kinase 2 (JAK2) hematopoiesis-signaling pathway disruptsbone marrow production of blood cells, leading to anemia, fatigue and splenomegaly.Until recently, the dual JAK1/JAK2 inhibitor, ruxolitinib (RUX), has been the onlyapproved pharmacological therapy for intermediate/high-risk MF. However, manypatients receiving RUX experience a suboptimal response or develop cytopenia, leadingto discontinuation. Fedratinib (FEDR), an oral, selective inhibitor with activity againstwild-type and mutationally activated JAK2 and the receptor tyrosine kinase FLT3, wasapproved in the US in August 2019. The real-world effectiveness of FEDR in the post-RUX setting has not yet been assessed. Aim: To assess the baseline characteristics and survival outcomes among patientsdiagnosed with MF who discontinued RUX and were subsequently treated with FEDR ornot. Methods : Adult US patients who received RUX after an initial diagnosis of primary MF(identified by ICD-9/10-CM codes) were identified using Flatiron Health's nationwideelectronic health record (EHR)-derived database. Patients were stratified by whetherthey subsequently received post-ruxolitinib fedratinib (FEDR group) or not (non-FEDRgroup). The non-FEDR group was further stratified by time of RUX discontinuation(before [non-FEDR subgroup A] and after [non-FEDR subgroup B] US approval of FEDRin August 2019) to enable a contemporaneous comparison with the FEDR group. Indexdate was the start of FEDR therapy in the FEDR group, and last date of RUX therapy inthe non-FEDR groups. Patients were included if they had ≥2 recorded visits in theFlatiron network on or after January 1, 2011- Oct 31, 2020; were aged ≥18 years atindex; had ≥1 months' data before and also after index; and had no record of receivingunclassified clinical study drugs prior to index. Patient demographics and clinical characteristics were assessed at index. Overall survival (OS) was defined as time fromindex until death or censoring, and was assessed by Kaplan-Meier analysis. Landmarksurvival was defined as the proportion of patients who survived at a given point.Association of baseline variables and survival were assessed by Cox proportionalhazards model and p Results: Overall, 229 MF patients were evaluated (FEDR group: n=70; non-FEDRgroup: n=159). The median age at index for the FEDR group and non-FEDR group was71.0 and 70.0 years, 55.7% and 50.3% were female, 64.3% and 68.6% were white, andmedian follow-up from index was 7.0 and 6.0 months, respectively. Among patients withEastern Cooperative Oncology Group performance status (ECOG PS) at index, 90.2%(46/51) and 74.3% (84/113) had an ECOG score of 0-1, respectively (Table). Median(range) duration of FEDR therapy in the FEDR group was 3.7 (0-12.2) months; 47.1%(33/70) of patients receiving FEDR initiated therapy with 400 mg FEDR once daily, and21.4% (15/70) initiated with 200 mg FEDR once daily. Median OS was not reached in theFEDR group and was 17 months in the non-FEDR group. Landmark survival in theFEDR and non-FEDR groups was 91.3% and 76.5% at 3 months, and 71.6% and 53.5%at 12 months, respectively. In the non-FEDR subgroup B, the corresponding survivalrates at 3 months and 12 months were 75.0% and 47.9%. The Cox proportional hazardsmodel suggested that being male, 'other' (non-white, non-black/African-American, non-Asian, non-missing) race, Charlson comorbidity index ≥1, ECOG score 2-4, and bodymass index Conclusions: This real-world analysis demonstrates that these two groups of patientswith primary MF who had received prior RUX had broadly comparable baselinecharacteristics. FEDR appeared to be associated with improved survival up to 1 yearafter index compared with non-FEDR therapy. When the FEDR group and non-FEDR Bsubgroup were compared, the differences in survival rate remained. FEDR may offersubstantially improved survival probability in patients receiving post-ruxolitinib therapy of primary MF in routine clinical practice. Figure 1 Figure 1. Disclosures Passamonti: Novartis: Research Funding, Speakers Bureau; Celgene: Research Funding, Speakers Bureau. Do: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Lou: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Chevli: Bristol-Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Abraham: Bristol Myers Squibb: Current Employment.

Background: Until recently, ruxolitinib (RUX) was the only drug approved for treatment of intermediate- or high-risk myelofibrosis (MF). Many patients discontinue RUX due to lack of response, loss of efficacy, or intolerance. Fedratinib (INREBIC) is an oral, selective kinase inhibitor with activity against mutant and wild-type JAK2 and FLT3. Fedratinib is approved in the United States, Canada, European Union, United Kingdom, and elsewhere as front-line therapy for treatment of patients with JAK-inhibitor-naïve MF and those previously treated with RUX. In the single-arm, phase 2 JAKARTA2 trial of fedratinib 400 mg/day (starting dose) in patients with MF relapsed, refractory, or intolerant to prior RUX, 31% of pts achieved a spleen volume response and 27% achieved a symptom response with fedratinib (Harrison, Am J Hematol 2020). Gastrointestinal (GI) events were among the most common adverse events (AEs) reported during fedratinib treatment in JAKARTA2. A clinical hold was placed on fedratinib in November 2013 due to suspected cases of Wernicke encephalopathy (WE); the hold was later lifted but long-term data, including survival outcomes, are limited for fedratinib. Two phase 3 trials, FREEDOM (NCT03755518) and FREEDOM2 (NCT03952039) are ongoing to assess the safety and efficacy of fedratinib in patients with MF previously treated with RUX. Unlike earlier studies of fedratinib, these two trials prospectively include GI-directed mitigation strategies and thiamine monitoring and supplementation. Preliminary data from the single-arm FREEDOM trial show reduced incidence of GI AEs with these mitigation strategies (Gupta, CLML 2020). Here we describe the study design and methods for the FREEDOM2 trial, the first trial to compare fedratinib vs. active MF therapies. Study Design and Methods: The ongoing multicenter, open-label, randomized, phase 3 FREEDOM2 trial is enrolling patients with MF in the European Union, China, Russia, South Korea, and Australia. Key eligibility criteria include age ≥ 18 years; primary, post-polycythemia vera (post-PV), or post-essential thrombocythemia (post-ET) MF; DIPSS Intermediate-2 or High-risk disease; splenomegaly, defined as spleen volume ≥ 450 cm 3 by MRI/CT and palpable spleen measuring ≥ 5 cm below the left costal margin; ECOG PS score ≤ 2; and platelet count ≥ 50 ×10 9/L (Figure). Patients must have been relapsed or refractory to prior RUX treatment for ≥ 3 months, or intolerant to RUX after ≥ 28 days of treatment (i.e., developed RBC transfusion dependence [≥ 2 units/month for 2 months] or grade ≥ 3 thrombocytopenia, anemia, or hematoma/hemorrhage). Eligible patients are randomized 2:1 to receive fedratinib 400 mg/day or investigator-selected best available therapy (BAT), including RUX or other approved JAK inhibitors, in repeated 28-day treatment cycles (Figure). Spleen volume is assessed by MRI/CT scan at screening, end of cycles (EOC) 3, 6, 12, 18, 24, and at the end of treatment. The primary endpoint is spleen volume response rate (SVRR), the proportion of patients in each arm achieving a ≥ 35% reduction in spleen volume from baseline at EOC6, and the key secondary endpoint is MF symptom response rate, the proportion of patients achieving a ≥ 50% reduction from baseline in total symptom score (TSS) on the Myelofibrosis Symptom Assessment Form (MFSAF) at EOC6. Other secondary endpoints include durations of spleen volume and symptom responses, reductions in spleen size by palpation, overall and progression-free survival, effectiveness of the risk mitigation strategies for GI AEs and WE, patient-reported health-related quality of life (HRQoL) measures, and safety. Exploratory endpoints include relationships between fedratinib efficacy and prognostic markers (eg, mutations) and pharmacodynamic activity (eg, circulating cytokines, hematopoietic cell profiling). Patients in the BAT arm can cross-over to receive fedratinib after EOC6, or before EOC6 if the patient experiences confirmed progression of splenomegaly. As the first trial to compare fedratinib against other active therapies for MF, results from FREEDOM2 are eagerly anticipated. As of June 2021, 135 patients had been randomized, with enrollment expected to be completed by the end of 2021. Figure 1 Figure 1. Disclosures Benevolo: BMS: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Speakers Bureau. Vannucchi: Incyte: 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; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Harrison: CTI BioPharma: 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, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Geron: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sierra Oncology: Honoraria; Incyte Corporation: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Promedior: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Constellation Pharmaceuticals: Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Keros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Galacteo: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Loschi: CELGENE/BMS: Honoraria; AbbVie: Ended employment in the past 24 months, Honoraria; Gilead: Ended employment in the past 24 months, Honoraria; Novartis: Ended employment in the past 24 months, Honoraria; Servier: Ended employment in the past 24 months, Honoraria; MSD: Honoraria. Al-Ali: Incyte: Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; Pfizer: Consultancy; AbbVie: Consultancy, Honoraria. Bonifacio: Amgen: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Cervantes: Bristol Myers Squibb: Consultancy, Honoraria. Wrobel: Novartis: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Roche: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; BeiGene: Honoraria, Speakers Bureau. Kiladjian: AbbVie: Consultancy; AOP Orphan: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: 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. Verstovsek: PharmaEssentia: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Ital Pharma: Research Funding; Incyte Corporation: Consultancy, Research Funding; NS Pharma: Research Funding; Blueprint Medicines Corp: Research Funding; Celgene: Consultancy, Research Funding; CTI BioPharma: Research Funding; Protagonist Therapeutics: Research Funding; Promedior: Research Funding; Roche: Research Funding; AstraZeneca: Research Funding; Sierra Oncology: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Constellation: Consultancy; Pragmatist: Consultancy. Mesa: Promedior: Research Funding; Pharma: Consultancy; Gilead: Research Funding; CTI: Research Funding; CTI: Research Funding; Novartis: Consultancy; Sierra Oncology: Consultancy, Research Funding; Incyte Corporation: Consultancy, Research Funding; Celgene: Research Funding; Constellation Pharmaceuticals: Consultancy, Research Funding; AOP: Consultancy; Abbvie: Research Funding; La Jolla Pharma: Consultancy; Samus: Research Funding; Genentech: Research Funding. Rose: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Gharpure: Bristol Myers Squibb: Current Employment. Hernandez: Bristol Myers Squibb: Current Employment. Zhang: Bristol Myers Squibb: Current Employment. Passamonti: BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: 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.

BACKGROUND. HCV-positive DLBCL has distinct clinical and pathologic characteristics compared to its negative counterpart: patients (pts) are usually older with more frequent splenic and extranodal involvement and elevated LDH. Differently from its clinical hallmarks, the molecular landscape of this pathological entity has been scarcely outlined. METHODS. In this bicentric study, we investigated the clinical and molecular features and outcome of 54 pts with HCV-positive DLBCL. Targeted next generation sequencing (NGS) was performed on DNA extracted from formalin-fixed paraffin-embedded tissue biopsies. A core panel probes covering coding exons from 184 genes frequently mutated in mature B cell neoplasms was designed using IDT tool and libraries were prepared using Illumina DNA-prep-with enrichment. Sequencing was performed on Illumina HiSeq 2500. Cluster analysis was performed using LymphGen tool. We also applied fluorescence in situ hybridization (FISH) for MYC, BCL2 and BCL6. RESULTS. Median age was 71 (33-84; IQR: 61.9-77). Stage was III/IV in 34 pts (63%). Extranodal sites were involved in 21 pts (38%), spleen in 20 pts (37%). LDH was higher than the upper limit in 40 pts (74%). R-IPI was good for 2 pts (4%), intermediate for 24 pts (44%), poor for 28 pts (52%). HPS score was intermediate or high in 33 of 44 assessed pts (75%). A histological low-grade component was identified in 15 pts (27%). Hans algorithm differentiated pts almost equally in GCB (26/50, 52%) and non-GCB (24/50, 48%) subtype. HCV-RNA was detectable in 52 pts (96%) and quantifiable in 43 pts (79%). Of 29 pts assessed, genotype was 1 in 9 (31%), 2 in 16 (55%), 3 in 4 pts (14%). Among 37 pts whose data were available, 11 pts (30%) received direct antiviral agents, 7 pts (19%) received interferon-containing regimen, 19 pts (51%) were not treated for HCV. Twenty-seven pts (50%) received rituximab-enriched protocols, 23 pts (43%) were treated with chemotherapy alone, 1 pt (2%) with surgery alone, 3 pts (5%) were lost to follow up. With a median follow up of 7.7 years (yrs) (IQR: 4.6-10.6), 5-yrs overall survival (OS) (95%CI) was 49.3% (34.1-62.8%) and 5-yrs progression free survival (PFS) (95%CI) was 39.5% (25.5-53.3%). Median OS and PFS were 4.9 and 3.1 yrs, respectively. FISH analysis showed lack of BCL2 (0/19) and MYC translocations (0/15). BCL6 fusions were found in 76% of pts (16/21). NGS showed mutations in 154 of the 184 analyzed genes. The informativity of the panel was 100% with all pts presenting at least one oncogenic variant. Gene mutation frequencies are presented in Fig. 1. The median mutation load (MML) was 13 mutated genes per case (2-32; IQR: 9-16). Most frequently mutated genes were the epigenetic regulators KMT2D, mutated in 23 pts (42.6%), and SETD1B, mutated in 17 pts (31.5%). FAS, PM1 and RERE were mutated in 15 pts each (27.8%). TBL1XR1, BCL11A and SGK1 were mutated in 14 (26%), 13 (24%) and 12 pts (22%), respectively. Considering genes in their specific pathway, 94% of pts harbored mutations in genes involved in epigenetic regulation (MML: 3; range 1-7; IQR: 1.25-4), 90% of pts in apoptosis-related genes (MML: 2; 1-7; IQR: 1-3) and 77% of pts in genes belonging to BCR/NFkB signaling pathway (MML: 2; 1-7; IQR: 1-3). Of note, 56% of pts carried mutations in genes related to immune regulation (MML: 1.7; 1-5; IQR: 1-2) and 25% of pts had mutations within the NOTCH pathway (MML: 1.2; range 1-2). Via the LymphGen 1.0 tool, we classified 26 pts (48%) into 4 genetic clusters: BN2 (11/26, 42%), ST2 (8/26, 31%), MCD (4/26, 15%), EZB (3/26, 12%). Twenty-eight pts (52%) were classified as "others". Among those belonging to BN2 cluster, 7 pts (64%) had a histologically confirmed transformed DLBCL. No significant differences in terms of OS and PFS were identified according to cluster subgroups. CONCLUSIONS. The prevalence of the BN2 cluster and enrichment of mutations of genes involved in NOTCH pathway seem to indicate a preferential marginal-zone origin in HCV-positive DLBCL. In addition, our data confirm the absence of BCL2 translocation in this subset of DLBCL and show a high prevalence of mutated genes within the epigenetic and immune regulation pathways in HCV-positive DLBCL, pointing out their compelling role in the pathogenesis and suggesting potential implications for molecularly targeted therapies. Figure 1 Figure 1. Disclosures Passamonti: Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: 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. Arcaini: Celgene: Speakers Bureau; Gilead Sciences: Research Funding; Bayer, Celgene, Gilead Sciences, Roche, Sandoz, Janssen-Cilag, VERASTEM: Consultancy; Celgene, Roche, Janssen-Cilag, Gilead: Other: Travel expenses.

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.

Context: Pelabresib (CPI-0610), a first-in-class, oral, small-molecule inhibitor of BET proteins (BETi), has potential to promote disease-modifying activity through altered gene regulation of key oncogenic, fibrotic, and inflammatory factors in MF. Treatment with JAKi ruxolitinib (rux) or fedratinib in the frontline setting is associated with approximately 30–40% splenic response (spleen volume reduction ≥ 35% [SVR35]) at 6 months. BETi pelabresib monotherapy demonstrated clinical activity in heavily pre-treated MF pts. Therefore, combination of pelabresib with rux is expected to achieve higher SVR35 response rate in JAKi treatment-naive MF pts. Objective: Evaluation of pelabresib in combination with rux in JAKi treatment-naive MF pts. Design: Pts with MF who were not previously treated with JAKi were enrolled in Arm 3 of MANIFEST. The primary endpoint is SVR35 response at wk 24. Pts were treated with pelabresib 125 mg daily on days 1–14 in a 21-day cycle in combination with rux, which was dosed based on the baseline platelet count. Results: As of 29 September 2020, 78 pts were treated, and 66 pts were ongoing. Baseline characteristics were mean age: 67 years; 72% male; primary MF: 54% pts; DIPSS ≥Int-2: 76% pts; IPSS ≥Int-2: 83%; Hgb Conclusions: Pelabresib treatment in combination with rux in JAKi treatment-naive MF pts resulted in spleen volume reduction that was greater than what would be expected with rux alone, regardless of baseline patient disease and demographic characteristics.

The role of interleukin-6 (IL-6) in tumorigenesis and in particular in haematological malignancies is crucial. On the basis of the favourable results obtained in the subset of multicentric Castleman disease (MCD), Siltuximab, a chimeric, human-murine, immunoglobulin (Ig) Gk monoclonal antibody directed against human IL-6 has been evaluated in haematological malignancies such as multiple myeloma, myelodisplastic syndromes and non Hodgkin lymphomas. Areas covered: This review discusses available data related to the role of IL-6 as a therapeutic target, the characteristics of Siltuximab in term pharmacokinetics and pharmacodynamics properties and a detailed analysis of the studies involving haematological malignancies with a peculiar focus on non Hodgkin lymphoma. Expert opinion: The results obtained with Siltuximab in haematological malignancies and in particular with non Hodgkin lymphoma are inferior to those obtained in MCD. The complex interaction between malignant clones, inflammatory background and host response could justify this difference. New interesting areas of study are the role of Siltuximab in early phase of multiple myeloma (smoldering multiple myeloma) and if there may be a possible future application in the treatment of Waldenström macroglobulinemia.

Introduction: MF is a clonal stem cell disorder characterized by progressive bone marrow failure, extramedullary hematopoiesis, and debilitating constitutional symptoms. Approximately 60% of pts develop anemia within a year of diagnosis; pts who are transfusion dependent have worse survival and quality-of-life outcomes (Tefferi A, et al. Mayo Clin Proc 2012;87:25-33). Treatment for MF-associated anemia remains critically unaddressed, with no approved therapies available. Luspatercept is a first-in-class erythroid maturation agent that has been shown to increase hemoglobin and reduce transfusion burden in pts with myelodysplastic syndromes (Fenaux P, et al. N Engl J Med 2020;382:140-51) and β-thalassemia (Cappellini MD, et al. N Engl J Med 2020;382:1219-31). Pts have also achieved multiple response episodes with luspatercept (Fenaux P, et al. Blood 2019;134:841). We previously reported findings from the ongoing open-label, phase 2 ACE-536-MF-001 trial evaluating luspatercept in pts with MF-associated anemia (Gerds AT, et al. Blood 2019;134:557). Here we report updated study results, focusing on response in pts requiring RBC transfusions. Methods: 79 pts with MF and anemia were enrolled (Figure). Of these, 43 were requiring RBC transfusions, defined as 6-12 U/84 d prior to treatment, or 4-12 U/84 d for the 3 expansion cohort pts. Pts in Cohort 3B received a stable ruxolitinib (RUX) dose for ≥ 16 wks (40 wks for expansion cohort pts), whereas Cohort 2 pts did not (Figure). Pts in Cohort 3B received a median RUX dose of 20 mg/d (range 5-40) for a median of 73 wks (range 29-359) prior to treatment. Pts received luspatercept every 21 d at a starting dose of 1.0 mg/kg (1.33 mg/kg for 3 expansion cohort pts in Cohort 3B), with doses escalating up to 1.75 mg/kg; 81% and 50% of pts in Cohorts 2 and 3B escalated to 1.75 mg/kg. Primary endpoint for pts receiving transfusions was RBC transfusion-independence (RBC-TI) for ≥ 12 consecutive wks within the first 24 wks on study. However, as responses were observed that did not fall within the 24-wk response window, additional assessments were conducted for the entire treatment duration for RBC-TI and ≥ 50% decrease in RBC transfusions (minimum 4 RBC U decrease) from baseline. Intent-to-treat data were analyzed as of March 29, 2020. Results: Pts in Cohorts 2 and 3B received a median of 8 cycles of luspatercept (range 1-39), for a median (mean) duration of 24 (31) and 23 (39) wks, respectively. Pts in Cohorts 2 and 3B received a median of 2.7 RBC U/28 d (range 1-5) and 2.7 RBC U/28 d (range 2-4), respectively. For the primary endpoint, 2/21 (10%) and 6/22 (27%) pts receiving transfusions in Cohorts 2 and 3B achieved RBC-TI over any consecutive 12 wks during the first 24 wks. Median time to start of first RBC-TI response period in Cohorts 2 and 3B was 1.5 days and 37 days; median duration of response was 49 wks (range 16-82) and 42 wks (range 12-111), respectively. When assessing the entire treatment period, 4/21 (19%) and 8/22 (36%) pts in Cohorts 2 and 3B achieved RBC-TI ≥ 12 wks, respectively. 25% of the RBC-TI responders in both cohorts experienced 2 separate episodes of RBC-TI ≥ 12 wks. Median cumulative duration of all individual ≥ 12-wk response episodes of RBC-TI was 59 wks (range 24-82) in Cohort 2 and 55 wks (range 12-116) in Cohort 3B. 8/21 (38%) and 10/22 (46%) pts in Cohorts 2 and 3B achieved a ≥ 50% reduction in RBC transfusion burden (minimum ≥ 4 U reduction) over 12 wks; of these, 38% and 20% of responders in Cohorts 2 and 3B experienced 2 separate ≥ 12-wk response episodes, and 1 pt (13%) in Cohort 2 experienced 3 separate responses. 4/15 (27%) and 8/14 (57%) pts in Cohorts 2 and 3B who reached 24 wks of treatment achieved clinical benefit and therefore continued luspatercept on an ongoing basis. Safety is reported for all 79 pts on study. 5 (6%) pts had grade 3-4 treatment-related adverse events (AEs); these AEs were diarrhea (n = 2), dehydration (n = 1), and hypertension (n = 3). There were no treatment-related deaths. Treatment-related AEs (any grade) occurring in ≥ 5% of pts were hypertension (13%), bone pain (9%), and diarrhea (5%). 8 (10%) pts had ≥ 1 AE leading to discontinuation. 16 (20%) pts remain on treatment. Conclusions: These longer-term findings suggest durable activity of luspatercept in pts with MF-associated anemia. In addition, a quarter of pts receiving transfusions achieved more than one ≥ 12-wk episode of RBC-TI response with luspatercept. The incidence of grade 3-4 AEs with luspatercept was low. Disclosures Gerds: Roche/Genentech: Research Funding; Celgene: Consultancy, Research Funding; Sierra Oncology: Research Funding; AstraZeneca/MedImmune: Consultancy; Incyte Corporation: Consultancy, Research Funding; Pfizer: Research Funding; Apexx Oncology: Consultancy; CTI Biopharma: Consultancy, Research Funding; Gilead Sciences: Research Funding; Imago Biosciences: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Blueprint: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees. Passamonti:Novartis: Speakers Bureau; BMS: Speakers Bureau; Roche: Other: Support of parent study and funding of editorial support. Kremyanskaya:Constellation Pharmaceuticals: Research Funding; Incyte Corporation: Research Funding; Bristol Myers Squibb: Research Funding; Protagonist Therapeutics: Consultancy, Research Funding; Astex Pharmaceuticals: Research Funding. Gotlib:CTI Biopharma: Research Funding; Kartos: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Roche: Honoraria, Research Funding; BMS: Research Funding. McCaul:BMS: Speakers Bureau; Seattle Genetics: Speakers Bureau; Karyopharm: Speakers Bureau; Incyte: Speakers Bureau. Ribrag:argenX: Research Funding; pharmamar: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; servier: Consultancy; nanostring: Honoraria, Membership on an entity's Board of Directors or advisory committees; gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; AZD: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other; Infinity: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: 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; MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; gustave roussy comprehensive cancer center: Current Employment; EPZ: Honoraria, Membership on an entity's Board of Directors or advisory committees; epizyme (EPZ): Research Funding. Mead:Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; Celgene/BMS: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding; Abbvie: Consultancy; CTI: Consultancy; Gilead: Consultancy. Harrison:Roche: Honoraria; Gilead Sciences: Honoraria, Speakers Bureau; Incyte Corporation: Speakers Bureau; Janssen: Speakers Bureau; CTI Biopharma Corp: Honoraria, Speakers Bureau; Sierra Oncology: Honoraria; Celgene: Honoraria, Research Funding, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; AOP Orphan Pharmaceuticals: Honoraria; Promedior: Honoraria. Mesa:Sierra Oncology: Consultancy; LaJolla Pharmaceutical Company: Consultancy; Novartis: Consultancy; Incyte: Research Funding; CTI BioPharma: Research Funding; Genentech: Research Funding; AbbVie: Research Funding; Promedior: Research Funding; Bristol Myers Squibb: Research Funding; Samus Therapeutics: Research Funding. Kiladjian:AbbVie: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Barosi:Bristol Myers Squibb: Consultancy. Gerike:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Shetty:BMS: Current Employment, Current equity holder in publicly-traded company. Pariseau:Bristol Myers Squibb: Current Employment. Miranda:Bristol Myers Squibb: Current Employment. Schwickart:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Giuseppi:BMS: Current Employment, Current equity holder in publicly-traded company. Zhang:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Backstrom:Acceleron Pharma: Current Employment, Current equity holder in publicly-traded company; BMS: Current equity holder in publicly-traded company. Verstovsek:AstraZeneca: Research Funding; Roche: Research Funding; CTI Biopharma Corp: Research Funding; Genentech: Research Funding; Incyte Corporation: Consultancy, Research Funding; NS Pharma: Research Funding; Novartis: Consultancy, Research Funding; PharmaEssentia: Research Funding; ItalPharma: Research Funding; Sierra Oncology: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Blueprint Medicines Corp: Research Funding; Promedior: Research Funding; Gilead: Research Funding; Protagonist Therapeutics: Research Funding.

BACKGROUND RUX, a JAK 1/2 inhibitor, is a second-line treatment for symptom management and control of trilineage expansion in patients (pts) with PV who are resistant or intolerant to hydroxyurea (HU). In the RESPONSE study, RUX showed a superior and durable response in controlling hematocrit (HCT) and improving splenomegaly in PV pts resistant or intolerant to HU. RESPONSE-2 (NCT02038036) is a multicenter, open-label, Phase 3 trial comparing RUX with best available therapy (BAT) in HU-resistant/intolerant PV pts without splenomegaly. The primary analysis at Week (Wk) 28 and follow-ups at Wks 80 and 156 proved superiority of RUX over BAT. Here we present the final study results of the 5-year follow-up (Wk 260). METHODS Pts were randomized (1:1) to RUX 10 mg twice daily or BAT; crossover from BAT to RUX was allowed from Wk 28. The final analysis at Wk 260 evaluated durability of HCT control, complete hematologic response (CHR), and safety. Durability of HCT control was defined as absence of phlebotomy eligibility from Wk 8 to Wk 260 with ≤1 phlebotomy eligibility post-randomization to Wk 8. CHR was defined as HCT control with a white blood cell count RESULTS Pts were randomized to RUX (n=74) or BAT (n=75). A total of 59/74 RUX pts and 61/75 BAT pts completed the treatment duration. Among the 75 BAT pts, 58 pts crossed over to RUX, with 38 of them completing the study, allowing for long-term follow-up of 97 pts treated with RUX. Median (range) exposure was 260.0 (0.1 - 273.1) wks in RUX, 28.4 (6.7 - 83.0) wks in BAT, and 224.7 (2.7 - 236.1) wks in crossover arms. At Wk 260, 21.6% of RUX pts (16/74) achieved durable HCT control. The Kaplan-Meier (KM) -estimated median duration of HCT control was not reached (Fig. A). Durable CHR was achieved in 24.3% of RUX pts (18/74; estimated median duration, 34.0 wks). Crossover pts derived RUX benefit by achieving HCT control with HCT levels decreasing over time (median HCT was 46.2% at the crossover baseline and 38.9% at the end of treatment). JAK2 V617F allele burden reduced over time for pts treated with RUX from baseline with a median decrease of 14.8% in RUX (59 evaluable pts) and 13.5% in crossover arms (42 evaluable pts). RUX showed durable improvement in PV-associated symptoms; about 45% of RUX pts continued to achieve ≥50% reduction in MPN-SAF TSS at Wk 260. RUX pts also continued to experience improvements in all 5 dimensions of the EQ-5D-5L assessment. Total number of phlebotomies was 60 in the RUX arm (at Wk 260) vs 106 for BAT (Wk 80). At Wk 260, RUX- (vs BAT-) treated pts required >0 − ≤2 phlebotomies in 16.2% (vs 38.7%), >2 − ≤4 in 9.5% (vs 21.3%), >4 − ≤6 in 5.4% vs (2.7%), and >6 − ≤8 in none (vs 1.3%). The most common AEs (>5%, exposure-adjusted rate) were anemia, arthralgia, and increased weight in the RUX arm and anemia, and hypertension in pts after crossover. Of note, exposure-adjusted rates of herpes zoster were 3.9 in both RUX (Grade 3/4, 0.9) and crossover pts (no Grade 3/4) and none in the BAT arm. The exposure-adjusted rate of thromboembolic events was higher with BAT than RUX (3.7 vs 1.5). As expected given prior HU exposure, non-melanoma skin cancer was the most common secondary malignancy in RUX (exposure-adjusted rates: randomized, 2.7; crossover, 2.9) and BAT-treated pts (1.9). No RUX pts developed AML, whereas myelofibrosis was reported in 2 pts (exposure-adjusted rate, 0.6%). On-treatment death was reported in 5 pts: 1 each in the RUX arm (metastatic melanoma) and BAT arm (septic shock), and 3 in crossover (1 pt each - cardiac disorder, general health deterioration, and PV progression). The KM-estimated median overall survival was not reached in both RUX (95.8%; 95% CI: 87.4, 98.6) and BAT arms (90.7%; 95% CI: 80.3, 95.7; Fig. B) at ≥260 wks. Transformation-free survival (KM-estimated, 95% CI) in the RUX arm was 94.18% (85.23, 97.78) at ≥260 wks. CONCLUSIONS In line with the RESPONSE study outcomes, final analysis from the 5-yr follow-up of RESPONSE 2 proved superiority of RUX over BAT with a safety profile that remained consistent with previous reports. RUX provided durable HCT control with a decrease in the need for phlebotomies, CHR, improved PV-associated symptoms and PRO scores, with fewer thromboembolic events in PV pts without splenomegaly, who are HU resistant or intolerant. Disclosures Palandri: Novartis: Consultancy, Honoraria. Callum:Canadian Blood Services: Research Funding; Octapharma Canada: Research Funding. Devos:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Vannucchi:AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Blueprint: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Zor:Novartis: Current Employment. Gilotti:Novartis: Current Employment. Zhang:Novartis: Current Employment. Griesshammer:Celgene: Honoraria, Speakers Bureau; AOP Orphan: Honoraria, Speakers Bureau; CTI: Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

Introduction: Momelotinib (MMB) is a potent JAK1, JAK2 and ACVR1 inhibitor with clinical activity against the three hallmark features of myelofibrosis (MF), namely anemia, constitutional symptoms and splenomegaly, across the continuum of intermediate/high risk MF patients whether JAKi--naïve or previously JAKi-treated as demonstrated in the previously conducted Phase 3 SIMPLIFY-1 & -2 clinical trials (S1, S2). S1 was conducted in JAKi-naïve MF patients (n=432) randomized 1:1 to MMB or ruxolitinib (RUX) over a 24-week double-blind dosing period. S2 was conducted in MF patients who experienced hematological toxicity during prior RUX therapy (n=156) randomized 2:1 to MMB or best available therapy (BAT; consisting of RUX in 88% of patients) over a 24-week open-label dosing period. In both trials, following the 24-week randomized treatment (RT) period, patients originally randomized to MMB could continue MMB therapy (MMB→MMB) and those randomized to RUX/BAT were eligible to cross-over to MMB (RUX/BAT→MMB) for additional extended treatment (ET). Over 820 MF patients have received MMB during the compound's clinical development program. Methods: Long term outcome data from S1 and S2 are reported here including survival, response endpoints, and MMB exposure. Overall survival (OS) and leukemia free survival (LFS) were followed for a maximum of approximately 5 years (median of 2.9 years in S1 and 2.3 years in S2). Following participation in S1 and S2, patients were eligible to continue MMB therapy via an extended access protocol (XAP), along with additional Phase 2 MMB subjects. Duration of exposure incorporates XAP data but OS/LFS analyses only include data obtained within S1 and S2. Results: Of the 137 Phase 2 and 3 patients who have enrolled in XAP, 105 remain on MMB with duration on therapy ranging up to 10 years. Across the RT and ET periods of S1 and treatment in XAP, 69% of the 215 JAKi-naïve patients randomized to MMB remained on therapy for ≥ 48 weeks; 44% for ≥ 96 weeks and 30% for ≥ 144 weeks. Of the 104 prior JAKi-exposed subjects randomized to MMB in S2, 47% received MMB (RT, ET and XAP) for ≥ 48 weeks; 25% for ≥ 96 weeks and 17% for ≥ 144 weeks. In both S1 and S2, OS and LFS were similar between treatment groups (stratified HR for OS of 0.99 in S1, 0.96 in S2), demonstrating robust and consistent survival outcomes for patients who commenced JAKi therapy with MMB and those dosed initially with RUX/BAT followed by MMB (Figure 1). In addition, the median OS in S2 (MMB arm of 34.3 months) compares very favorably with previously reported median survival ranging from 13-30 months in patients who have discontinued RUX (Tang, ASH 2019). In S1, splenic response, defined as a reduction in spleen volume of ≥ 35% from baseline at Week 24 was achieved by 26.5% of patients in the MMB group and 29.5% in the RUX group (non-inferiority p The ability to achieve or maintain transfusion independence (TI) represents a substantive clinical benefit in light of the progressive myelosuppression associated with MF. In the RT period of both S1 and S2, a greater proportion of subjects receiving MMB compared with the control arm achieved TI at Week 24, defined as no RBC transfusion and no Hgb level below 8 g/dL in of the prior 12 weeks. The proportion who were TI at Week 24 was approximately 70% for MMB vs 54% for RUX in S1, and 44% for MMB vs 27% for BAT/RUX in S2. For MMB→MMB subjects in S1, the RBC transfusion free rate at Week 48 (ET) was approximately 75% and 67% for RUX→MMB. Similarly, in S2, MMB→MMB subjects had an RBC transfusion free rate of approximately 55% and 40% for BAT/RUX→MMB. For the patients who achieved TI at any time during the study, the median duration of TI response by KM estimate was not reached in S1 and was >1 year in S2. Conclusion: In conclusion, further analyses of data from the 550 JAKi-naïve and previously JAKi-treated patients with MF who received MMB in RT and/or ET show robust long-term survival, sustained efficacy and durability of dosing consistent with MMB's differentiated pharmacological profile. These data demonstrate MMB's potential ability to durably address the unmet needs of patients with intermediate/high risk MF. Disclosures Verstovsek: NS Pharma: Research Funding; Promedior: Research Funding; CTI Biopharma Corp: Research Funding; Sierra Oncology: Consultancy, Research Funding; Blueprint Medicines Corp: Research Funding; PharmaEssentia: Research Funding; AstraZeneca: Research Funding; ItalPharma: Research Funding; Protagonist Therapeutics: Research Funding; Roche: Research Funding; Incyte Corporation: Consultancy, Research Funding; Gilead: Research Funding; Novartis: Consultancy, Research Funding; Genentech: Research Funding; Celgene: Consultancy, Research Funding. Lech-Marańda:Roche, Amgen, Gilead: Speakers Bureau; Roche, Novartis, Takeda, Janssen-Cilag, Amgen, Gilead, AbbVie, Sanofi: Consultancy. Sacha:Incyte: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Adamed: Consultancy, Honoraria; Bristol-Myers Squibb Company: Consultancy, Honoraria, Speakers Bureau. Oh:Constellation: Consultancy; Kartos Therapeutics: Consultancy; Disc Medicine: Consultancy; PharmaEssentia: Consultancy; CTI Biopharma: Consultancy; Incyte Corporation: Consultancy; Gilead Sciences: Consultancy; Novartis: Consultancy; Celgene/Bristol Myers Squibb: Consultancy; Blueprint Medicines: Consultancy. Harrison:Celgene: Honoraria, Research Funding, Speakers Bureau; Sierra Oncology: Honoraria; Janssen: Speakers Bureau; Roche: Honoraria; Promedior: Honoraria; CTI Biopharma Corp: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; AOP Orphan Pharmaceuticals: Honoraria; Shire: Honoraria, Speakers Bureau; Incyte Corporation: Speakers Bureau. McLornan:NOVARTIS: Honoraria, Speakers Bureau; JAZZ PHARMA: Honoraria, Speakers Bureau; CELGENE: Honoraria, Speakers Bureau. McMullin:Abbvie: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy; Celgene: Consultancy; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Kowalski:Sierra Oncology Inc.: Current Employment, Current equity holder in publicly-traded company. Smith:Sierra Oncology Inc.: Current Employment, Current equity holder in publicly-traded company. Mesa:Bristol Myers Squibb: Research Funding; Promedior: Research Funding; AbbVie: Research Funding; Sierra Oncology: Consultancy; CTI BioPharma: Research Funding; Samus Therapeutics: Research Funding; Genentech: Research Funding; Incyte: Research Funding; LaJolla Pharmaceutical Company: Consultancy; Novartis: Consultancy.

Background: Momelotinib (MMB) is a potent, orally bioavailable, small-molecule inhibitor of JAK1, JAK2, and ACVR1 with demonstrable clinical activity against the three hallmark features of myelofibrosis (MF), namely anemia, constitutional symptoms, and splenomegaly, across the continuum of intermediate-/high-risk MF patients whether JAKi-naive or previously JAKi-treated. Objective: To characterize the long-term safety of MMB in comparison to ruxolitinib (RUX). Methods: SIMPLIFY-1 was a double-blind, randomized, study of MMB vs RUX in intermediate-/high-risk JAKi-naive patients with MF (n=215 MMB, 217 RUX). SIMPLIFY-2 (S2) was a randomized study of MMB vs best available therapy (BAT; RUX in 88% of patients) in prior RUX-treated patients with hematological toxicity (n=104 MMB, 52 BAT). Randomized treatment (RT) for 24 weeks was followed by open-label MMB extended treatment in both studies. Data from RT were compared, and further long-term data were analyzed from 550 subjects receiving MMB, including 336 subjects on MMB for ≥48 weeks and 148 for ≥144 weeks. Results: Despite treatment duration exceeding 3.5 years for >90 subjects, the incidence of grade 3/4 hematological toxicity was very low. During the S1 RT period, grade 3/4 anemia occurred in only 6.1% of MMB subjects compared with -4-fold higher rate (22.7%) for RUX. Dose reductions due to thrombocytopenia were also 4-fold higher for RUX (24.5%) than MMB (6.1%). Subjects randomized to MMB in S1 experienced a rapid, sustained increase in hemoglobin, in contrast to significant hemoglobin decrease on RUX. Following crossover to MMB from RUX, hemoglobin increased rapidly to above baseline. Platelet values were also significantly higher compared to RUX. Similarly, in S2, hemoglobin and platelet values were maintained or improved on MMB. Importantly, no new safety signals and no cumulative toxicity were observed during extended MMB dosing. Rates of peripheral neuropathy remained low. Conclusions: MMB displays very favorable long-term tolerability, including an absence of significant rates of high-grade hematological and other toxicities or evidence of cumulative toxicity, consistent with its differentiated pharmacological and clinical profile. Notably, subjects switching from RUX also experienced favorable tolerability, despite their previous therapy.