RP-1664

RP-1664 is an oral small molecule kinase inhibitor from Repare Therapeutics. A first-in-class, highly selective oral inhibitor of Polo-like kinase 4 (PLK4), a synthetic-lethal target linked to TRIM37 overexpression. Its furthest stage is phase 1, for advanced solid tumours, with and without TRIM37 amplification. ClinicalTrials.gov registers it in one study linked below. Phase 1 LIONS NCT06232408 terminated ('Sponsor decided to terminate study early'). Preliminary data were presented at the AACR-NCI-EORTC meeting in October 2025. In November 2025 Repare said it was trying to license or dispose of the programme; Repare was acquired by XenoTherapeutics in January 2026. Whether it works in people has not been established unless a trial below reports it.