Inobrodib
Oral p300/CBP inhibitor in development by CellCentric for relapsed/refractory multiple myeloma.
Last refreshed: 13 May 2026
Could inobrodib be the first drug to block the p300/CBP pathway in cancer?
Timeline for inobrodib
CellCentric raises Europe's largest 2026 biotech round
UK Startups and Innovation- What is inobrodib and how does it treat multiple myeloma?
- inobrodib is an oral drug that blocks two enzymes called p300 and CBP, which cancer cells use to control gene expression. CellCentric is testing it in patients with relapsed multiple myeloma who have run out of standard treatment options.Source:
- What stage is the inobrodib clinical trial at?
- inobrodib is in the Phase 2 DOMMINO-1 trial at sites in the UK and US as of May 2026. A Phase 3 study called DOMMINO-2 is planned for the second half of 2026.Source:
- Who developed inobrodib and what company makes it?
- inobrodib was developed by CellCentric, a Cambridge-based biotechnology company. It is also known by its development code CCS1477.Source: CellCentric official
- Why does blocking p300 and CBP help treat cancer?
- p300 and CBP are enzymes that regulate which genes are switched on in a cell. Many cancer cells depend on these proteins to maintain the gene-expression patterns that drive their growth. Blocking them disrupts those programmes and can cause cancer cells to stop proliferating.Source: Scientific literature
Background
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.