Improved transfusion independence rates for momelotinib versus ruxolitinib in anemic JAKi naïve myelofibrosis patients independent of baseline platelet or transfusion status

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Background: Momelotinib (MMB) is a potent JAK1, JAK2 and ACVR1 inhibitor with clinical activity against the hallmark features of myelofibrosis (MF), namely anemia, constitutional symptoms and splenomegaly, across the continuum of JAKi naïve or previously JAKi treated intermediate/high risk MF patients as demonstrated in the previously conducted Phase 3 SIMPLIFY-1 & -2 clinical trials (S1, S2). S1 was conducted in JAKi-naïve patients with MF (n = 432) double-blind randomized 1:1 to MMB or ruxolitinib (RUX). MMB demonstrated a statistically non-inferior splenic response rate (SRR) to RUX at the W24 landmark analysis in S1 but did not meet significance for total symptom score (TSS) response. Low SRR and TSS response was observed for RUX in patients with low platelets, while MMB elicited consistent SRR and TSS response across the platelet subsets, comparable to the response in the ITT. Transfusion independence (TI) at W24 was higher for MMB vs RUX patients across all PLT strata. Methods: Progressive anemia is a common occurrence in MF with nearly all MF patients requiring transfusions as their disease advances. Given the prognostic importance of Hgb and transfusion status in MF patients including evidence that achieving or maintaining transfusion independence by Week 24 with momelotinib is associated with improved OS in S1 and S2, we expanded the previously reported retrospective platelet subset analysis to explore the W24 TI response rates for MMB and RUX randomized patients in S1 by baseline Hgb and PLT levels and transfusion status. Results: The data presented here suggest that the prognostically-important W24 TI rate was substantively higher in anemic patients receiving MMB versus RUX, irrespective of the degree of anemia. MMB is also more effective relative to RUX in achieving or maintaining TI in JAKi naïve patients irrespective of baseline PLT count or baseline transfusion status. Conclusions: Together with data suggesting that TI response at W24 with momelotinib is associated with a survival advantage, these data further support the potential TI benefits of inhibiting ACVR1 in addition to JAK1 and JAK2 with MMB in MF patients. Clinical trial information: NCT01969838, NCT02101268. [Table: see text]

Is there an impact of measurable residual disease as assessed by multiparameter flow cytometry on survival of AML patients treated in clinical practice? A population-based study

The Swedish national guidelines for treatment of acute myeloid leukemia (AML) recommend analysis of measurable residual disease (MRD) by multiparameter flow cytometry (MFC) in bone marrow in the routine clinical setting. The Swedish AML registry contains such MRD data in AML patients diagnosed 2011-2019. Of 327 patients with AML (non-APL) with MRD-results reported in complete remission after two courses of intensive chemotherapy 229 were MRD-negative (70%), as defined by <0.1% cells with leukemia-associated immunophenotype in the bone marrow. MRD-results were reported to clinicians in real time. Multivariate statistical analysis adjusted for known established risk factors did not indicate an association between MFC-MRD and overall survival (HR: 1.00 [95% CI 0.61, 1.63]) with a median follow-up of 2.7 years. Knowledge of the importance of MRD status by clinicians and individualized decisions could have ameliorated the effects of MRD as an independent prognostic factor of overall survival.

Clinical and genomic characterization of patients diagnosed with the provisional entity acute myeloid leukemia with BCR-ABL1, a Swedish population-based study

Acute myeloid leukemia (AML) with t(9;22)(q34;q11), also known as AML with BCR-ABL1, is a rare, provisional entity in the WHO 2016 classification and is considered a high-risk disease according to the European LeukemiaNet 2017 risk stratification. We here present a retrospective, population-based study of this disease entity from the Swedish Acute Leukemia Registry. By strict clinical inclusion criteria we aimed to identify genetic markers further distinguishing AML with t(9;22) as a separate entity. Twenty-five patients were identified and next-generation sequencing using a 54-gene panel was performed in 21 cases. Interestingly, no mutations were found in NPM1, FLT3, or DNMT3A, three frequently mutated genes in AML. Instead, RUNX1 was the most commonly mutated gene, with aberrations present in 38% of the cases compared to around 10% in de novo AML. Additional mutations were identified in genes involved in RNA splicing (SRSF2, SF3B1) and chromatin regulation (ASXL1, STAG2, BCOR, BCORL1). Less frequently, mutations were found in IDH2, NRAS, TET2, and TP53. The mutational landscape exhibited a similar pattern as recently described in patients with chronic myeloid leukemia (CML) in myeloid blast crisis (BC). Despite the concomitant presence of BCR-ABL1 and RUNX1 mutations in our cohort, both features of high-risk AML, the RUNX1-mutated cases showed a superior overall survival compared to RUNX1 wildtype cases. Our results suggest that the molecular characteristics of AML with t(9;22)/BCR-ABL1 and CML in myeloid BC are similar and do not support a distinction of the two disease entities based on their underlying molecular alterations.

Failure matters: unsuccessful cytogenetics and unperformed cytogenetics are associated with a poor prognosis in a population-based series of acute myeloid leukaemia

Unsuccessful cytogenetics (UC) in patients with acute myeloid leukaemia (AML) treated on different SWOG trials was recently reported to be associated with increased age and dismal outcome. To ascertain whether this holds true also in unselected patients with AML, we retrieved all cytogenetic reports in cases from the population-based Swedish AML Registry. Between 1997 and 2006, 1737 patients below 80 yr of age without myelosarcoma or acute promyelocytic leukaemia received intensive treatment. The frequencies of UC and unperformed cytogenetics (UPC) were 2.1% and 20%, respectively. The early death rates differed between the cytogenetic subgroups (P = 0.006) with the highest rates in patients with UC (14%) and UPC (12%) followed by high-risk (HR) AML, intermediate risk (IR) and standard risk (SR) cases successfully karyotyped (8.6%, 5.9%, and 5.8%, respectively). The complete remission rate was lower in UC and UPC and HR compared with the other risk groups (P < 0.001). The overall five-year survival rates were 25% for UC and 22% for UPC, whereas the corresponding frequencies for SR, IR and HR AML patients without UC and UPC were 64%, 31% and 15%, respectively. In conclusion, lack of cytogenetic data translates into a poor prognosis.