For Healthcare Professionals

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


About the study

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.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


Inclusion Criteria:

  1. Aged ≥ 18 years
  2. Confirmed diagnosis of myelofibrosis (primary, post-polycythemia vera, or post essential thrombocythemia)
  3. Adequate hematologic, renal, and hepatic function
  4. 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
  5. Prognostic risk-factor score of Intermediate-1 or higher per Dynamic International Prognostic Scoring System (DIPSS) scoring system
  6. Spleen volume of ≥ 450 cm^3
  7. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2


Exclusion Criteria:

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

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Study Locations

Enter your ZIP code/Postal code/PIN code to locate study sites near you:

How to Apply

Contact the study center to learn if this study is a good match for you.

Study’s details


Myelofibrosis,Primary Myelofibrosis,Post-polycythemia Vera Myelofibrosis,Post-essential Thrombocythemia Myelofibrosis

Age (in years)



Phase 3

Participants needed


Est. Completion Date

Apr 30, 2027

Treatment type



Constellation Pharmaceuticals identifier


Study number

CPI 0610-04

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