Phase 3 Study of Pelabresib (CPI-0610) in Myelofibrosis (MF) (MANIFEST-2)

Inclusion Criteria:

• Aged ≥ 18 years

• Confirmed diagnosis of myelofibrosis (primary, post-polycythemia vera, or postessential thrombocythemia)

• Adequate hematologic, renal, and hepatic function

• Have at least 2 symptoms with an average score ≥ 3 or an average total score of ≥ 10over the 7-day period prior to randomization using the MFSAF v4.0

• Prognostic risk-factor score of Intermediate-1 or higher per Dynamic InternationalPrognostic 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 prohibittreatment

• Had prior treatment with any JAKi or BET inhibitor for treatment of amyeloproliferative neoplasm