The CellCentric p300/CBP inhibitor, CCS1477, is an orally available drug in early development for advanced prostate cancer, and is structurally distinct from the p300/CBP inhibitor we covered in Apr. 2020. In agreement with its proposed MoA, it impacts AR and MYC signaling in serial tumor biopsies acquired from its first-in-human Ph. I trial. It will be interesting to see whether the agent is able to demonstrate a significant survival and quality-of-life benefit in late-stage disease given the likely on-target effects of p300/CBP inhibition on certain healthy cells.