Inobrodib

inobrodib (also known as CCS1477) is an orally administered small-molecule inhibitor of p300 and CBP, two closely related histone acetyltransferase enzymes that play a central role in transcriptional regulation. By blocking these proteins, inobrodib disrupts gene-expression programmes that cancer cells rely on for proliferation and survival. It was developed by Cambridge-based CellCentric as a targeted therapy for haematological malignancies, particularly relapsed or refractory multiple myeloma — a blood cancer that becomes progressively harder to treat after each line of therapy.

CellCentric's £220m Series B in May 2026 — Europe's largest biotech venture round of the year — is primarily funding inobrodib's clinical programme. The drug is currently in the Phase 2 DOMMINO-1 trial at sites in the UK and US, with a Phase 3 DOMMINO-2 study planned for H2 2026. If Phase 3 succeeds, inobrodib could become the first approved p300/CBP inhibitor, opening a new mechanism class for the estimated 35,000 patients diagnosed with multiple myeloma annually in the UK and US combined.