Apalutamide for High-Risk Localized Prostate Cancer Following Radical Prostatectomy (Apa-RP).

Approximately 25 to 50% of patients with high-risk localized prostate cancer experience biochemical recurrence within 2 years of radical prostatectomy. The Apa-RP study (NCT04523207) investigated whether adjuvant apalutamide plus androgen deprivation therapy in high-risk patients who have undergone radical prostatectomy improved biochemical recurrence-free survival.

Apa-RP was a multicenter, open-label, single-arm, phase 2 study conducted in community urology practices in the United States. High-risk patients who had radical prostatectomy received 12 cycles of apalutamide (240 mg daily; 28-day cycles) plus androgen deprivation therapy. The primary endpoint was biochemical recurrence-free survival. Secondary endpoints included testosterone recovery (≥150 ng/dL) and safety.

One hundred eight patients were enrolled; median age was 66.0 years (range 46.0-77.0). Median pre-operative prostate specific antigen and baseline testosterone were 7.6 ng/mL (range 2.2-62.7) and 340.0 ng/dL (range 43.0-939.0), respectively. The biochemical recurrence-free rate at 24 months (12 months after completion of planned therapy) was 100% (90% CI 93-100). Serum testosterone recovery rate (≥50 and ≥150 ng/dL) 12 months after treatment completion was 96% (95% CI 88-98) and 77% (95% CI 66-85), respectively. Overall, 107 (99%) patients experienced treatment-emergent adverse events, with 24 (22%) experiencing grade 3 to 4 events.

In Apa-RP, BCR-free survival was 100% with 77% of patients having testosterone recovery (≥150 ng/dL) within 12 months of actual treatment completion and a manageable safety profile. These results provide proof of concept that treatment intensification with 12 cycles of apalutamide plus ADT could become an option for patients with high-risk localized prostate cancer who have undergone radical prostatectomy.

The Journal of urology. 2024 Aug 01 [Epub ahead of print]

Neal Shore, Jason Hafron, Daniel Saltzstein, Gordon Brown, Laurence Belkoff, Pankaj Aggarwal, Jennifer Phillips, Amitabha Bhaumik, Tracy McGowan

Carolina Urologic Research Center, Myrtle Beach, South Carolina., Michigan Institute of Urology, West Bloomfield, Michigan., Urology San Antonio, San Antonio, Texas., New Jersey Urology, Voorhees, New Jersey., Division of Urology, MidLantic Urology/Main Line Health, Bala Cynwyd, Pennsylvania., Janssen Scientific Affairs, Horsham, Pennsylvania., Janssen Research and Development, Titusville, New Jersey.