SW-3431

SW-3431 (formerly RPT04402) is an investigational, first-in-class small molecule molecular glue designed to activate specific complexes of protein phosphatase 2A (PP2A). PP2A is a central serine/threonine phosphatase that acts as a tumor suppressor; its activity can be lost in various cancers due to mutations that disrupt complex formation. SW-3431 promotes the assembly and activation of PP2A complexes, restoring their phosphatase activity and thereby suppressing oncogenic signaling pathways. Preclinical studies have shown that SW-3431 induces rapid, deep, and durable tumor regressions in models of rare uterine cancers—particularly those with PP2A mutations such as uterine carcinosarcoma (UCS) and uterine serous carcinoma (USC), which are aggressive subtypes with poor outcomes. The drug is being developed for molecularly defined subsets of endometrial cancer patients with high unmet need[1][3][4][6].