After an additional year of follow up, the authors here provide updated safety and PFS data on the 1207 men with nmCRPC with PSA doubling time <10 months who were randomized to receive apalutamide or placebo. Upon initial progression, patients had the option to receive open-label treatment with abiraterone provided by the sponsor. At the time of this report, the median treatment duration on apalutamide was 25.7 months and 11.5 months on placebo. In terms of safety, no new safety signals have been observed. Notable grade 3 treatment-emergent adverse events included rash (5.2%), falls (2.4%), and fractures (3.1%). 412 patients have discontinued apalutamide thus far. The most common reason was progressive disease (53%), followed by adverse events (25%), and withdrawal by patient (16%).
An important endpoint described here was PFS2, the timefrom randomization to time to disease progression on the subsequent therapy. Median time of progression on subsequent therapy after apalutamide was not yet reached, compared to 39.3 months for patients initially randomized to placebo (HR, 0.5; 95% CI, 0.390.63; p < 0.0001).
Apalutamide continues to show benefit for patients with nmCRPC, not only for increasing metastasis-free survival, but also for increasing PFS2, with a favorable side effect profile. With data coming out this GU ASCO on darolutamide, there will soon be three options (enzalutamide, apalutamide, darolutamide) for patients with nmCRPC and patient factors will be important to consider which is the best-personalized option.
Presented by: Eric J. Small, MD, FASCO, UCSF Helen Diller Family Comprehensive Cancer Care Center
Discussant: Nicholas J. van As, MBBCH, MRCP, FRCR, MD(res), Institute of Cancer Research and The Royal Marsden NHS Foundation Trust
Written By: Jason Zhu, MD. Fellow, Division of Hematology and Oncology, Duke University, Twitter: @TheRealJasonZhu at the 2019 American Society of Clinical Oncology Genitourinary Cancers Symposium, (ASCO GU) #GU19, February 14-16, 2019 - San Francisco, CA
- Smith MR, Saad F, Chowdhury S, et al. Apalutamide Treatment and Metastasis-free Survival in Prostate Cancer. New England Journal of Medicine 2018;378:1408-18.