RC-3940-II

RC-3940-II is a synthetic peptide **antagonist of bombesin/gastrin-releasing peptide (BN/GRP) receptors**, originally developed for oncology research. It potently inhibits proliferation of various cancer cell lines, particularly colon and breast carcinomas, by blocking BN/GRP-induced receptor signaling. Mechanistically, RC-3940-II leads to cell cycle arrest (notably S-phase accumulation) and impairs tumor growth in vitro and in vivo. It also displays efficacy in experimental models of benign prostatic hyperplasia, reducing prostate volume and altering key growth and inflammatory pathways. Preclinically, it synergizes with chemotherapeutic agents such as 5-fluorouracil and irinotecan. It has not advanced to late-stage clinical development and is not approved for use.[1][2][3][4]