Abiraterone acetate plus prednisone in non-metastatic biochemically recurrent castration-naïve prostate cancer

• Published in: European journal of cancer (1990) 2021-11, Vol.157, p.259-267
• Main Authors: Spetsieris, Nicholas, Boukovala, Myrto, Alafis, Ioannis, Davis, John, Zurita, Amado, Wang, Xuemei, Tu, Shi-Ming, Chapin, Brian F., Aparicio, Ana, Corn, Paul, Wang, Jennifer, Subudhi, Sumit K., Araujo, John, Papadopoulos, John, Pruitt, Lisa, Weldon, Justin A., Logothetis, Christopher J., Efstathiou, Eleni
• Format: Article
• Language: English
• Subjects: Abiraterone acetate; Abiraterone Acetate - administration & dosage; Acetic acid; Adult; Aged; Aged, 80 and over; Androgen Antagonists - administration & dosage; Androgen deprivation therapy; Androgens; Antigens; Antineoplastic Combined Chemotherapy Protocols - administration & dosage; Biochemically recurrent prostate cancer; Biochemistry; Castration; Chemoradiotherapy, Adjuvant - methods; Confidence intervals; Deprivation; Disease-Free Survival; Drug Administration Schedule; Follow-Up Studies; Hormone-naïve prostate cancer; Humans; Kallikreins - blood; Male; Metastases; Middle Aged; Neoplasm Recurrence, Local - blood; Neoplasm Recurrence, Local - diagnosis; Neoplasm Recurrence, Local - epidemiology; Neoplasm Recurrence, Local - therapy; Patients; Prednisone; Prednisone - administration & dosage; Prostate cancer; Prostate-specific antigen; Prostate-Specific Antigen - blood; Prostatectomy; Prostatic Neoplasms - blood; Prostatic Neoplasms - diagnosis; Prostatic Neoplasms - mortality; Prostatic Neoplasms - therapy; PSA-free survival; Radiation therapy; Survival; Time Factors; Time to PSA relapse
• ISSN: 0959-8049; 1879-0852
• DOI: 10.1016/j.ejca.2021.06.017

Intermittent androgen deprivation therapy (ADT) in biochemically recurrent castration-naïve prostate cancer is non-inferior to continuous therapy. We hypothesised that finite-duration abiraterone acetate plus prednisone (Abi +P) added to ADT will further reduce the duration of treatment exposure by prolonging time to prostate-specific antigen (PSA) recurrence without impacting eugonad state recovery. This phase II, randomised, open-label trial enrolled patients with rising PSA ≥ 0.2 ng/ml after radical prostatectomy and/or a PSA ≥ 1 following radiotherapy. Patients were randomised 1:1 to receive Abi (1 g PO daily) + P (5 mg PO daily) + ADT or ADT alone for 8 months. The primary end-point was PSA-free survival difference at 1 year following completion of therapy. Between February 2013 and July 2016, 200 patients were enrolled. Of 100 patients randomised to each arm, 99 in the Abi +P arm and 98 in the ADT arm were evaluable. Median follow-up was 64.4 months. Median PSA-free survival was 27.0 months for the Abi +P-treated group versus 19.9 months for the ADT-treated group (hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.47–0.87). The PSA-free survival at 1 year post-treatment completion was 98% for the Abi +P group and 88% for the ADT group. Median time to eugonad state was 13.1 months for the abiraterone-treated group and 12.8 months for the ADT-treated group. Median eugonad PSA-free survival was 12.5 months for the abiraterone-treated group versus 9.0 for the ADT-treated group (HR 0.72, 95% CI 0.53–0.98). There were no significant between-group differences in androgen deprivation-related adverse events. In men with biochemically recurrent prostate cancer following definitive treatment of the primary, finite duration treatment with ADT and Abi +P results in a significantly longer PSA relapse-free interval than treatment with ADT alone. •This trial investigated abiraterone in biochemically recurrent prostate cancer.•All patients had castration-naïve disease.•Abiraterone was added to ADT for 8 months.•This led to a significantly increased PSA-free survival compared to ADT alone.•The interval to subsequent systemic prostate cancer treatment was thus prolonged.