A Phase 1/2 Study of CPI-0610 With and Without Ruxolitinib in Patients With Hematologic and Myeloproliferative Malignancies
Key claim: A Phase 1/2 trial evaluated pelabresib (CPI-0610), a BET bromodomain inhibitor, as monotherapy and in combination with ruxolitinib in patients with myelofibrosis and essential thrombocythemia, establishing early clinical evidence for this therapeutic approach.
Abstract
Phase 1 Part: This was an open-label, sequential dose escalation study of pelabresib (CPI-0610) in patients who had previously been treated for Acute Leukemia, Myelodysplastic/Myeloproliferative Neoplasms.
Phase 2 Part: This was an open-label study of pelabresib (CPI-0610), administered with and without Ruxolitinib, in patients diagnosed with Myeloproliferative Neoplasms (Myelofibrosis and Essential Thrombocythemia).
Pelabresib (CPI-0610) was a small molecule inhibitor of bromodomain and extra-terminal (BET) proteins.
Why this matters
This early-phase trial supplies the foundational clinical safety/efficacy data for pelabresib that underwrites the subsequent Phase 3 MANIFEST-2 and DAK539 programs in myelofibrosis, while also testing BET inhibition in ET — a subtype where disease-modifying options remain limited. By spanning MF and ET in one Phase 1/2 framework, it demonstrates a shared mechanistic rationale across these MPN subtypes and frames pelabresib as a cross-subtype platform rather than a MF-only agent.