CellCentric, a clinical-stage biotechnology company, has completed patient enrollment in the randomized dose optimization portion of its Phase 1/2 clinical trial evaluating inobrodib in combination with pomalidomide and dexamethasone for multiple myeloma treatment. The milestone positions the first-in-class oral p300/CBP inhibitor for registration-enabling studies, with initial data expected by year-end 2025.
Study Design and Enrollment Completion
The Phase I/IIa open-label trial (NCT04068597) is evaluating the safety and efficacy of inobrodib both as monotherapy and in combination in patients with advanced hematological malignancies, predominantly multiple myeloma. A total of 60 patients have been enrolled in the multiple myeloma dose optimization cohorts, evaluating three separate doses of inobrodib at 20mg, 30mg, and 40mg in combination with standard doses of pomalidomide and dexamethasone.
"This achievement marks the final, critical step in preparing inobrodib for registration-enabling studies and positions us for the next phase of value creation," said Tomasz Knurowski, CellCentric's Chief Medical Officer. "With enrollment now complete across all dose-optimization cohorts, we can refine our dosing strategy with confidence."
Clinical Efficacy Data
Results from the dose escalation portion of the study were presented at ASH 2024, where the inobrodib, pomalidomide, and dexamethasone combination (InoPd) demonstrated a 75% overall response rate in the highest dose cohort. The dose optimization results will determine the recommended dose for future registration-enabling studies of inobrodib.
Novel Combination Approaches
Earlier in September 2025, CellCentric announced that the first patients had been dosed with inobrodib in combination with bispecific antibodies, marking the first time a novel mechanism of action has been combined with bispecifics in multiple myeloma. Additional treatment combinations are currently being assessed.
Drug Profile and Mechanism
Inobrodib is an oral small molecule drug that targets p300/CBP, lowering the expression of key cancer drivers, including MYC and IRF4. The drug has been evaluated in over 400 patients to date and demonstrates a favorable safety and tolerability profile. Clinical activity has been observed in multiple settings, including both solid tumor and hematologic malignancies.
The oral capsule formulation allows for easy patient administration at home without the need for intensive monitoring. This differentiated profile may broaden use among patients who cannot tolerate or access other treatments, while its ease of administration could reduce healthcare system burden relative to more complex therapies.
Company Background
CellCentric is a privately held biotechnology company headquartered in the UK with expanding U.S. operations. The company maintains development and commercial rights to inobrodib and is supported by a global syndicate of life science investors, including RA Capital Management, Forbion, Morningside, Pfizer Ventures, Avego, and the American Cancer Society's BrightEdge Fund.
