This post-approval commitment study addressed the limited data on the safety and efficacy of apalutamide in Chinese patients with non-metastatic castration-resistant prostate cancer (NM-CRPC). Utilizing a double-blinded, placebo-controlled trial with pre-planned crossover design, 75 patients were randomized (2:1) to receive apalutamide 240 mg daily or placebo while continuing androgen deprivation therapy. Apalutamide significantly reduced the risk of prostate-specific antigen (PSA) progression by 76.7% compared with placebo (hazard ratio [HR] = 0.233, p = 0.0052), with confirmed PSA response rate of 92.0% versus 12.0%. The median metastasis-free survival with apalutamide was 36.8 months, while the median overall survival was not reached. Grade 3 and 4 treatment-emergent adverse events were reported in 43.1% and 4.2% of patients, respectively, with hypertension, pneumonia, and rash being the most frequently reported, and the safety profile was consistent with existing data on apalutamide. Overall, these findings indicate that apalutamide is both efficacious and safe for Chinese patients, providing a valuable treatment option for high-risk NM-CRPC.