A Study of SHR2554 Alone or in Combination With SHR3680 in the Treatment of mCRPC

This is a multicenter, open, non-randomized and dose-escalating and -expansion Phase I/II trial and it studies the tolerance, PK and efficacy of SHR2554 alone or in combination with SHR3680 in the treatment of patients with metastatic Castration Resistant Prostate Cancer. The Phase I part is a dose-escalating study including Ia (dose-escalation monotherapy) and Ib (dose-escalation combination therapy). Approximately 18-30 patients in Phase Ia will only receive one of five dose levels of orally SHR2554. Approximately 30\~48 patients in Phase Ib trial will receive SHR2554 combined with SHR3680, in which 2\~3 different dose levels of SHR2554 will be selected based on the result of the Phase Ia. Phase II part is a dose-expansion study. Primary endpoints of the study are dose-limiting tolerance (DLT), maximum-tolerated dose (MTD) and prostate specific antigen (PSA) response rate.