Open AccessEfficacy and safety of abiraterone acetate plus prednisone in Japanese patients with newly diagnosed, metastatic hormone-naive prostate cancer: final subgroup analysis of LATITUDE, a randomized, double-blind, placebo-controlled, phase 3 study
Author(s) -
Hiroyoshi Suzuki,
Toshitaka Shin,
Satoshi Fukasawa,
Katsuyoshi Hashine,
Sumiko Kitani,
Noriyuki Ohtake,
Kazuhiro Shibayama,
NamPhuong Tran,
Suneel Mundle,
Karim Fizazi,
Nobuaki Matsubara
Publication year - 2020
Publication title -
japanese journal of clinical oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.768
H-Index - 85
eISSN - 1465-3621
pISSN - 0368-2811
DOI - 10.1093/jjco/hyaa030
Subject(s) - abiraterone acetate , medicine , prednisone , placebo , interim analysis , subgroup analysis , hazard ratio , prostate cancer , population , gastroenterology , urology , randomized controlled trial , cancer , confidence interval , androgen deprivation therapy , pathology , alternative medicine , environmental health
Background LATITUDE was a randomized, double-blind, international and phase 3 study of abiraterone acetate plus prednisone in patients with high-risk metastatic hormone-naïve prostate cancer. In the first interim analysis of LATITUDE (clinical cutoff date: 31 October 2016), significant prolongation in overall survival and radiographic progression-free survival (co-primary endpoints) was observed when compared with placebo. The results of the Japanese subgroup analysis of LATITUDE first interim analysis were consistent with those of the overall population. In this study, overall survival and safety results from the final analysis of the Japanese subgroup of the LATITUDE study are presented (clinical cutoff date: 15 August 2018). Methods Abiraterone acetate (1000 mg/day) and prednisone (5 mg/day) were administered orally in the abiraterone acetate plus prednisone group, and matching placebos in the placebo group. Results Of the 1199 patients included in LATITUDE, 70 constituted the Japanese subgroup (abiraterone acetate plus prednisone: n = 35, placebo: n = 35). Following a median (range) follow-up of 56.6 (2.5, 64.2) months, the median overall survival was not reached in both the treatment arms of the Japanese subgroup (hazard ratio: 0.61; 95% confidence interval: 0.27–1.42; nominal P = 0.2502). A total of 23 deaths (abiraterone acetate plus prednisone: 9 [25.7%], placebo group: 14 [40.0%]) were reported in Japanese subgroup. Grade 3/4 adverse events were reported in 24 (68.6%) and 9 (25.7%) patients in the abiraterone acetate plus prednisone and placebo groups, respectively. Conclusions In this Japanese subgroup analysis, addition of abiraterone acetate plus prednisone to androgen-deprivation therapy demonstrated favorable efficacy and safety outcomes in patients with newly diagnosed, high-risk metastatic hormone-naïve prostate cancer. Survival benefits observed in the Japanese subgroup first interim analysis were sustained long-term and were consistent with the overall population.