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Phase III

A Phase 3, Randomized, Double-blind, Active-Control Study of Pelabresib (CPI-0610) and Ruxolitinib vs. Placebo and Ruxolitinib in JAKi Treatment Naive MF Patients

  • Study HIC#:2000030483
  • Last Updated:11/15/2022

A Phase 3, randomized, blinded study comparing pelabresib (CPI-0610) and ruxolitinib with placebo and ruxolitinib in myelofibrosis (MF) patients that have not been previously treated with Janus kinase inhibitors (JAKi). Pelabresib is a small molecule inhibitor of bromodomain and extra-terminal (BET) proteins.

  • Start Date08/10/2022
  • End Date09/01/2022

Trial Purpose and Description

Primary Outcome Measures  :

  1. Splenic response at Week 24 [ Time Frame: 24 weeks of treatment ]The primary endpoint of the study is splenic response, defined as a ≥35% reduction from baseline in spleen volume as measured by magnetic resonance imaging (MRI) or computerized tomography (CT), at Week 24.

Secondary Outcome Measures  :

  1. Total Symptom Score response at Week 24 [ Time Frame: 24 weeks of treatment ]The key secondary endpoint of the study is Total Symptom Score response, defined as a ≥50% decrease from baseline in Total Symptom Score as measured by the Myelofibrosis Symptom Assessment Form v4.0, at Week 24. A higher Total Symptom Score indicates a higher disease burden and thus a worse outcome.

Eligibility Criteria

Inclusion Criteria:

  • Aged ≥ 18 years
  • Confirmed diagnosis of myelofibrosis (primary, post-polycythemia vera, or post essential thrombocythemia)
  • Adequate hematologic, renal, and hepatic function
  • Have at least 2 symptoms with an average score ≥ 3 or an average total score of ≥ 10 over the 7-day period prior to randomization using the MFSAF v4.0
  • Prognostic risk-factor score of Intermediate-1 or higher per Dynamic International Prognostic Scoring System (DIPSS) scoring system
  • Spleen volume of ≥ 450 cm^3
  • Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2

Exclusion Criteria:

  • Splenectomy or splenic irradiation in the previous 6 months
  • Chronic or active conditions and/or concomitant medication use that would prohibit treatment
  • Had prior treatment with any JAKi or BET inhibitor for treatment of a myeloproliferative neoplasm


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