TT125-802

TT125-802 is an orally available, selective, and potent small molecule inhibitor of the bromodomain of CBP and p300, two highly homologous lysine acetyltransferases that function as transcriptional co-activators. By inhibiting the CBP/p300 bromodomain, TT125-802 blocks transcriptional reprogramming in cancer cells—a key mechanism underlying non-genetic resistance to targeted therapies. This approach aims to prevent or delay the emergence of drug resistance in solid tumors and hematological malignancies. Preclinical studies have demonstrated efficacy as monotherapy in models of castration-resistant prostate cancer, KRAS-mutated colorectal cancer, and non-small cell lung cancer. The drug is currently being evaluated in a Phase 1 clinical trial for safety and tolerability as monotherapy across a range of advanced solid tumors, with plans for future combination studies alongside targeted agents such as KRAS, EGFR, or AR inhibitors.