A Phase 2 Trial of Abiraterone Acetate in Japanese Men with Metastatic Castration-resistant Prostate Cancer and without Prior Chemotherapy (JPN-201 Study)
Year: 2014
Type: article
Study design: Clinical Trial
Abstract: OBJECTIVE: Abiraterone acetate has been approved in >70 countries for chemotherapy-naïve metastatic castration-resistant prostate cancer patients. Efficacy and safety of abiraterone acetate (1000 mg/once daily) with prednisolone (5 mg/twice daily) in chemotherapy-naïve Japanese patients with metastatic castration-resistant prostate cancer was evaluated. METHODS: Men, ≥20 years, with prostate-specific antigen levels of ≥5 ng/ml and evidence of progression were enrolled in this Phase 2, multicenter, open-label study. Primary efficacy endpoint was proportion of patients achieving a prostate-specific antigen decline of ≥50% from baseline (prostate-specific antigen response) after 12 week of treatment. Secondary efficacy endpoints and safety were assessed. RESULTS: A confirmed prostate-specific antigen response was observed in 29/48 (60.4%) patients by week 12; lower limit of two-sided 90% confidence interval was >35% (threshold response rate), demonstrating efficacy of abiraterone acetate. Secondary efficacy endpoints: prostate-specific antigen response rate during treatment period: 62.5%; objective radiographic response, partial response: 4/18 (22.2%) patients; complete response: none; stable disease: 11/18 (61.1%) patients; median percent change in prostate-specific antigen level from baseline at Week 12: -66.62%. Median prostate-specific antigen response duration and progression-free survival were not reached, and median radiographic progression-free survival was 253 days. Of 31/48 (64.6%) patients experienced adverse events of special interest; most common was hepatic function abnormality (37.5%, Grade 3: 10.4%). One Grade 3 hypertension was the only mineralocorticoid adverse event >Grade 1/2. CONCLUSIONS: Efficacy of abiraterone acetate plus prednisolone was demonstrated by decline in prostate-specific antigen levels with evidence of antitumor activity by radiography in Japanese patients with chemotherapy-naïve metastatic castration-resistant prostate cancer. Abiraterone acetate plus prednisolone had an acceptable safety profile. CLINICAL TRIAL REGISTRATION NO: NCT01756638.
DOI: 10.1093/jjco/hyu149
Institutions: National Cancer Center Hospital East, Yokohama City University, Kindai University, Kitasato University, Toho University, Toho University Medical Center Sakura Hospital, Niigata University, Shikoku Cancer Center, Janssen Pharmaceutical K.K. (Japan), Hamamatsu University, Hamamatsu University School of Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, The University of Tokyo
Language: English
Subfield: Cancer Research
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,604
OpenAlex ID: W2119285946