Zenith Epigenetics Ltd. announced it has entered into an agreement with Astellas Pharma Inc. to evaluate ZEN-3694, Zenith's leading BET inhibitor, in combination with Astellas and Pfizer's androgen receptor inhibitor, XTANDI (enzalutamide), in patients with metastatic castration resistant prostate cancer (mCRPC). Under the terms of the agreement, Zenith will sponsor and conduct a Phase 2b randomized study to evaluate the efficacy of the combination of ZEN-3694 and enzalutamide relative to single agent enzalutamide in mCRPC patients who have progressed on a prior androgen receptor signaling inhibitor (ARSi). Astellas will supply enzalutamide for the trial and Zenith will retain all rights to ZEN-3694.