CTx-648

CTx-648 is a highly potent, selective, and orally bioavailable small molecule inhibitor of the histone lysine acetyltransferases KAT6A and KAT6B. It was developed to target cancers—particularly estrogen receptor positive (ER+) breast cancer—where KAT6A is frequently amplified or overexpressed. By inhibiting KAT6A/KAT6B activity, CTx-648 reduces acetylation of histone H3K23 (H3K23Ac), leading to downregulation of genes involved in estrogen signaling, cell cycle progression, Myc pathway activation, and stem cell pathways. Preclinical studies have demonstrated that CTx-648 induces significant tumor growth inhibition in ER+ breast cancer models—including those resistant to endocrine therapy—highlighting its potential as a novel therapeutic approach for patients with hormone therapy–refractory disease[1][3][5][7].