A Study of Momelotinib Versus Danazol in Symptomatic and Anemic Myelofibrosis Participants (MOMENTUM)

MOMENTUM is a randomized, double-blind, active control Phase 3 trial intended to confirm the differentiated clinical benefits of the investigational drug momelotinib (MMB) versus danazol (DAN) in symptomatic and anemic participants who have previously received an approved Janus kinase inhibitor (JAKi) therapy for myelofibrosis (MF). The purpose of this clinical study is to compare the effectiveness and safety of MMB to DAN in treating and reducing: 1) disease related symptoms, 2) the need for blood transfusions and 3) splenomegaly, in adults with primary MF, post-polycythemia vera MF or post-essential thrombocythemia MF. The study is planned in countries including, but not limited to: Australia, Austria, Belgium, Bulgaria, Canada, Czech Republic, Denmark, France, Germany, Hungary, Israel, Italy, New Zealand, Poland, Romania, Singapore, South Korea, Spain, Sweden, Taiwan, United Kingdom (UK) and United States (US). Participants must be symptomatic with a Myelofibrosis Symptom Assessment Form (MFSAF) version (v) 4.0 Total Symptom Score of \>= 10 at screening, and be anemic with hemoglobin (Hgb) \< 10 gram/deciliter (g/dL). For participants with ongoing JAKi therapy at screening, JAKi therapy must be tapered over a period of at least 1 week, followed by a 2-week non-treatment washout interval prior to randomization. Participants will be randomized 2:1 to orally self-administer blinded treatment: MMB plus placebo or DAN plus placebo. Participants randomized to receive MMB who complete the randomized treatment period to the end of Week 24 may continue to receive MMB in the open-label extended treatment period to the end of Week 204 (a total period of treatment of approximately 4 years) if the participants tolerates and continues to benefit from MMB. Participants randomized to receive DAN may cross-over to MMB open-label treatment in the following circumstances: at the end of Week 24 if they complete the randomized treatment period; or at the end of Week 24 if they discontinue treatment with DAN but continue study assessments and do not receive prohibited medications including alternative active anti-MF therapy; or at any time during the randomized treatment period if they meet the protocol-defined criteria for radiographically confirmed symptomatic splenic progression. Participants randomized to receive DAN who are receiving clinical benefit at the end of Week 24 may choose to continue DAN therapy up to Week 48. The comparator treatment, DAN, is an approved medication in the US and in some other countries and is recommended by national guidelines as a treatment for anemia in MF.