AUA 2018: Apalutamide Significantly Reduced Risk of PSA Progression in Patients With Nonmetastatic Castration-Resistant Prostate Cancer
A post-hoc analysis from the phase III SPARTAN study that showed treatment with apalutamide (Erleada) significantly reduced the risk of prostate-specific antigen (PSA) progression in patients with nonmetastatic castration-resistant prostate cancer (CRPC) who had a rapidly rising PSA while receiving continuous androgen-deprivation therapy (ADT) (Abstract PD10-11). These data were presented during the 113th Annual Meeting of the American Urological Association (AUA).
“Patients with nonmetastatic castration-resistant prostate cancer are at risk for metastases and mortality. In these patients, PSA doubling time is an important predictor of outcomes, including time to developing metastases or symptoms from their cancer,” said Eric Small, MD, FASCO, Professor of Medicine, Chief of the Division of Hematology and Oncology, and Deputy Director of the Helen Diller Comprehensive Cancer Center at the University of California, San Francisco, and co-principal investigator of the SPARTAN study. “This analysis further underscores the efficacy of apalutamide therapy and helps us understand how PSA changes in these patients are associated with clinical outcomes.”
Key Findings From SPARTAN
The SPARTAN trial was a phase III, randomized, double-blind, placebo-controlled, multicenter study that evaluated aplautamide in combination with ADT in patients with nonmetastatic CRPC who had a rapidly rising PSA (PSA doubling time ≤ 10 months). The primary endpoint was metastasis-free survival (MFS).
According to the data from the SPARTAN study presented at AUA 2018, apalutamide significantly decreased the risk of PSA progression by 94% compared with the placebo group (median not reached vs 3.71 months; hazard ratio [HR] = 0.06; 95% confidence interval [CI] = 0.05–0.08; P < .0001).
Additionally, the median time to PSA response was 29 days in the apalutamide plus ADT group. At 12 weeks after randomization, median PSA decreased by 90% in the apalutamide group and increased by 40% in the placebo group.
Among patients treated, baseline median PSA doubling time was 4.4 and 4.5 months, and median baseline PSA was 7.78 and 7.96 ng/mL in the apalutamide and placebo groups, respectively. A ≥ 90% maximum decline in PSA from baseline at any time on study was observed in 66% of patients in the apalutamide group and 1% of patients in the placebo group.
Apalutamide plus ADT improved MFS by 2 years (24.3 months) compared to placebo plus ADT (40.5 months vs 16.2 months; HR = 0.28; 95% CI, 0.23–0.35; P < .0001).
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
