SPARTAN, a phase 3 double-blind, randomized study of apalutamide (APA) versus placebo (PBO) in patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC).

161Background: Pts with nmCRPC are at risk for developing metastatic disease and cancer-specific mortality. There are no approved treatments for nmCRPC. APA is an orally administered next-generation androgen receptor inhibitor with antitumor activity in CRPC. SPARTAN evaluated the effects of APA on metastasis-free survival (MFS) in men with nmCRPC. Methods: Pts with nmCRPC and prostate-specific antigen doubling time (PSADT) of ≤ 10 mos were randomized 2:1 to APA (240 mg QD) or PBO. The primary end point was MFS, defined as the time from randomization to first radiographic distant metastasis (per blinded central review) or death. Secondary end points included time to metastasis (TTM), progression-free survival (PFS), time to symptomatic progression (SymProg), and overall survival (OS). Pts were eligible to receive study-provided abiraterone acetate plus prednisone after developing distant metastases. Second progression-free survival (PFS2, the time from randomization to disease progression or death after f...