MOMENTUM: Phase 3 randomized study of momelotinib (MMB) versus danazol (DAN) in symptomatic and anemic myelofibrosis (MF) patients previously treated with a JAK inhibitor.
Ruben A. Mesa, Aaron T. Gerds, Alessandro M. Vannucchi, Haifa Kathrin Al‐Ali, David Lavie, Andrew Kuykendall, Sebastian Grosicki, Alessandra Iurlo, Yeow Tee Goh, Mihaela Lazaroiu, Miklós Egyed, María Laura Fox, Donal P. McLornan, Andrew C. Perkins, Sung‐Soo Yoon, Vikas Gupta, Jean‐Jacques Kiladjian, Rafe Donahue, Jun Kawashima, Srđan Verstovšek
Abstract
7002 Background: MMB, an oral JAK1/2 and ACVR1/ALK2 inhibitor, showed clinical activity on MF symptoms, RBC transfusion requirements (anemia), and spleen volume in the SIMPLIFY trials. This pivotal phase 3 study of MF patients (pts) previously treated with a JAK inhibitor (JAKi) tested MMB vs DAN on key symptom, anemia, and spleen volume endpoints at 24 weeks (wks). Methods: Eligibility: Primary or post-ET/PV MF; DIPSS high risk, Int-2, or Int-1; MF Symptom Assessment Form Total Symptom Score (MFSAF TSS) ≥10; Hgb <10 g/dL; prior JAKi for ≥90 days, or ≥28 days if RBC transfusions ≥4 units in 8 wks or Gr 3/4 thrombocytopenia, anemia, or hematoma; palpable spleen ≥5 cm. Stratification: TSS, palpable spleen, and RBC units transfused. JAKi taper and washout was ≥21 days. Randomization: 2:1 to MMB 200 mg QD plus DAN placebo or DAN 600 mg QD plus MMB placebo for 24 wks, after which pts could receive open-label MMB. Assessments: Pt reported symptoms using a daily eDiary and spleen volume by MRI or CT. The primary endpoint was TSS response (≥50% reduction from baseline [BL]) rate at wk 24. Secondary endpoints, assessed sequentially at wk 24, were RBC transfusion independence (TI) rate, splenic response rate (SRR; ≥25% reduction in volume from BL), change from BL in TSS, SRR (≥35% reduction from BL) and rate of zero transfusions since BL. Results: 94 of 130 (72%) MMB pts and 38 of 65 (58%) DAN pts completed the 24-wk randomized treatment (RT) phase. Median BL TSS were 28 (MMB) and 26 (DAN), Hgb were 8.1 (MMB) and 7.9 (DAN) g/dL, and platelets were 97 (MMB) and 94 (DAN) x10 9 /L. BL TI was 13% (MMB) and 15% (DAN). Prior JAKi was ruxolitinib in 195 pts (100%) and fedratinib in 9 pts (5%). All primary and key secondary endpoints were met (Table). Most common Gr ≥3 TEAEs in the RT phase of the study were thrombocytopenia (MMB, 22%; DAN, 12%) and anemia (MMB, 8%; DAN, 11%). Gr ≥3 infections occurred in 15% of MMB and 17% of DAN pts. Peripheral neuropathy occurred in 5 (4%) of MMB (all Gr ≤2) and 1 (2%) of DAN (Gr ≤2) pts in the RT phase, and none discontinued study drug. Overall, TEAEs led to study drug discontinuation in 18% of MMB and 23% of DAN pts in RT phase. A trend toward improved OS up to wk 24 was seen with MMB vs DAN (HR=0.506, p=0.0719). Conclusions: In symptomatic and anemic MF pts, MMB was superior to DAN for symptom responses, transfusion requirements, and spleen responses with comparable safety and favorable survival. MMB may address a critical unmet need, particularly in MF pts with anemia. Clinical trial information: NCT04173494. [Table: see text]