SIMPLIFY-1: A Phase III Randomized Trial of Momelotinib Versus Ruxolitinib in Janus Kinase Inhibitor-Naïve Patients With Myelofibrosis

J Clin Oncol. 2017 Dec 1;35(34):3844-3850. doi: 10.1200/JCO.2017.73.4418. Epub 2017 Sep 20.

Abstract

Purpose We evaluated the efficacy and safety of momelotinib, a potent and selective Janus kinase 1 and 2 inhibitor (JAKi), compared with ruxolitinib, in JAKi-naïve patients with myelofibrosis. Patients and Methods Patients (N = 432) with high risk or intermediate-2 risk or symptomatic intermediate-1 risk myelofibrosis were randomly assigned to receive 24 weeks of treatment with momelotinib 200 mg once daily or ruxolitinib 20 mg twice a day (or per label), after which all patients could receive open-label momelotinib. The primary end point was a ≥ 35% reduction in spleen volume at 24 weeks of therapy. Secondary end points were rates of symptom response and effects on RBC transfusion requirements. Results A ≥ 35% reduction in spleen volume at week 24 was achieved by a similar proportion of patients in both treatment arms: 26.5% of the momelotinib group and 29% of the ruxolitinib group (noninferior; P = .011). A ≥ 50% reduction in the total symptom score was observed in 28.4% and 42.2% of patients who received momelotinib and ruxolitinib, respectively, indicating that noninferiority was not met ( P = .98). Transfusion rate, transfusion independence, and transfusion dependence were improved with momelotinib (all with nominal P ≤ .019). The most common grade ≥ 3 hematologic abnormalities in either group were thrombocytopenia and anemia. Grade ≥ 3 infections occurred in 7% of patients who received momelotinib and 3% of patients who received ruxolitinib. Treatment-emergent peripheral neuropathy occurred in 10% of patients who received momelotinib (all grade ≤ 2) and 5% of patients who received ruxolitinib (all grade ≤ 3). Conclusion In JAKi-naïve patients with myelofibrosis, 24 weeks of momelotinib treatment was noninferior to ruxolitinib for spleen response but not for symptom response. Momelotinib treatment was associated with a reduced transfusion requirement.

Publication types

  • Clinical Trial, Phase III
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Benzamides / administration & dosage*
  • Benzamides / adverse effects
  • Disease-Free Survival
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • Humans
  • Janus Kinase Inhibitors / administration & dosage*
  • Male
  • Maximum Tolerated Dose
  • Middle Aged
  • Patient Safety
  • Primary Myelofibrosis / drug therapy*
  • Primary Myelofibrosis / mortality*
  • Primary Myelofibrosis / pathology
  • Prognosis
  • Pyrazoles / administration & dosage*
  • Pyrazoles / adverse effects
  • Pyrimidines / administration & dosage*
  • Pyrimidines / adverse effects
  • Retreatment
  • Risk Assessment
  • Survival Analysis

Substances

  • Benzamides
  • INCB018424
  • Janus Kinase Inhibitors
  • Pyrazoles
  • Pyrimidines
  • N-(cyanomethyl)-4-(2-((4-(4-morpholinyl)phenyl)amino)-4-pyrimidinyl)benzamide