Study Comparing Pelabresib Plus Ruxolitinib Versus Ruxolitinib Alone in Adults with Myelofibrosis Without Prior JAK Inhibitor Treatment

What this Trial Is About

Researchers are evaluating whether combining pelabresib with ruxolitinib improves clinical outcomes compared to ruxolitinib alone in adults with primary myelofibrosis PMF, post-polycythemia vera myelofibrosis PPV-MF, or post-essential thrombocythemia myelofibrosis PET-MF who have not previously been treated with Janus kinase JAK inhibitors. This Phase 3 trial focuses on participants with intermediate or high-risk disease and assesses symptom burden and spleen size among other clinical measures. Participants begin with a screening period lasting up to 28 days to confirm eligibility and complete baseline tests. During the treatment phase, they are randomly assigned to receive either pelabresib orally once daily for 14 days of each 21-day cycle plus continuous ruxolitinib twice daily, or a matching placebo plus ruxolitinib. Treatment continues until unacceptable side effects, disease progression, or withdrawal. After treatment, a 30-day safety follow-up monitors for late side effects. Participants who have not experienced disease progression enter an efficacy follow-up with visits every 12 weeks for ongoing assessments including spleen imaging, lab tests, and bone marrow biopsies. Those with progression or new therapy start survival follow-up visits every 12 weeks, which may be remote, to monitor overall survival and disease status. The study includes comprehensive symptom scoring and spleen response evaluations over approximately three years.

A Phase 3 Study of Pelabresib (DAK539) and Ruxolitinib in Myelofibrosis (MF)