UK-based CellCentric has closed an oversubscribed USD 220 million Series D financing round to advance pivotal clinical development of inobrodib, its oral p300/CBP inhibitor for relapsed or refractory multiple myeloma. The round was led by Venrock Healthcare Capital Partners, with new investors Fidelity Management & Research Company, Sofinnova Partners, and HBM Healthcare joining existing backers RA Capital Management, Forbion, Pfizer, Avego BioScience Capital, and American Cancer Society BrightEdge.
Proceeds will support continued enrollment in the Phase II DOMMINO-1 study, evaluating inobrodib in combination with pomalidomide and dexamethasone — referred to as InoPd — in patients with relapsed or refractory multiple myeloma, as well as the planned initiation of the global Phase III DOMMINO-2 trial in H2 2026. Capital will also fund expansion of inobrodib into additional combination and maintenance treatment settings, including combinations with the bispecific T cell engagers elranatamab and teclistamab.
The Series D follows a USD 120 million Series C closed in May 2025 and a USD 35 million investment from RA Capital Management in July 2024, during which a USD 25 million loan note previously issued to Pfizer converted to equity. Earlier rounds include a Series B extension of approximately USD 33 million directed toward broadening clinical trials of the compound, then known as CCS1477.
Inobrodib is the company's sole clinical asset and represents a focused single-molecule strategy built around p300/CBP bromodomain inhibition. The p300 and CBP proteins function as transcriptional co-activators concentrated at super-enhancers that drive expression of key oncogenes, including MYC and IRF4, the latter being an established dependency in multiple myeloma. By occupying the bromodomain pocket of these proteins, inobrodib disrupts their recruitment to active chromatin, collapsing the transcriptional programs that myeloma cells rely on. The US FDA has previously granted inobrodib both Fast Track and orphan drug designations for relapsed or refractory multiple myeloma.