For this study, data on 519 patients with metastatic prostate cancer treated with degarelix from 17 controlled and uncontrolled trials were retrieved from a study repository. These patients all had metastatic disease and a PSA > 50 ng/mL treated with degarelix. The outcomes assessed were OS and PFS. Additionally, possible selection bias over time was also estimated. A Cox regression analysis was used to assess predictors of survival outcomes. Among these 519 patients meeting inclusion criteria, the median age was 71 years (IQR 65-77) and median PSA was 256 ng/mL (IQR 100-971). Survival at 36 months was 83% for patients with baseline PSA > 50 to < 200 ng/mL (n=233) and 72% for patients with baseline PSA > 200 ng/mL (n=286). The corresponding numbers for PSA-PFS at 36 months were 29% and 15%, respectively. A delayed separation of Kaplan-Meier estimates was observed between the PSA > 50 to < 200 ng/mL and > 200 ng/mL groups: 6 months for PSA-PFS and 12 months for survival. On Cox regression analysis, there was no significant effect of age (p = 0.20) or BMI (p = 0.33) on survival outcomes. The data suggest some selection bias over time in the most advanced patients.
Dr. Freedland concluded that 77% of patients with metastatic disease and PSA > 50 ng/mL who start degarelix treatment are alive after an observation period of 36 months. He cautions however that this is an analysis of uncontrolled data and as such a comparative randomized approach is required to allow potential comparison with other treatments.
Speaker: Stephen Freedland, Cedars-Sinai Medical Center, Los Angeles, CA
Co-Authors: Per Settergren Sørensen, Bo-Eric Persson
Written by: Zachary Klaassen, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, Twitter:@zklaassen_md at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA
1. Tombal B, Miller K, Boccon-Gibod L, et al. Additional analysis of secondary end point of biochemical recurrence rate in a phase 3 trial (CS21) comparing degarelix 80 mg versus leuprolide in prostate cancer patients segmented by baseline characteristics. Eur Urol 2010;57(5):836-842.