rucaparib + enzalutamide

**Rucaparib + enzalutamide** is an investigational combination therapy consisting of rucaparib, a small molecule poly(ADP-ribose) polymerase (PARP) inhibitor, and enzalutamide, a small molecule androgen receptor (AR) antagonist. Rucaparib blocks the PARP enzyme, impairing DNA repair in cancer cells and promoting synthetic lethality, particularly in cells with homologous recombination repair deficiencies. Enzalutamide inhibits androgen receptor signaling, blocking the growth-promoting effects of androgens on prostate cancer cells. The combination has been studied in metastatic castration-resistant prostate cancer (mCRPC), with the aim of enhancing anti-tumor efficacy by targeting DNA repair and androgen receptor pathways simultaneously. Early-phase clinical studies indicate an acceptable safety profile and preliminary efficacy, and a phase III clinical trial (CASPAR; NCT04455750) is underway to assess survival benefit compared to enzalutamide alone[1][2][3][4][5][6].