Identifying and Validating Surrogate Endpoints for Overall Survial (OS) in Metastatic Castration-Resistant Prostate Cancer

• Activity Number: 336 - Surrogate Endpoints: Bridging the Roles of Biology and Statistics for Clinical Outcome Prediction
• Type: Topic Contributed
• Date/Time: Tuesday, July 31, 2018 : 10:30 AM to 12:20 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Xiaowei Guan* and Michelle Casey and De Phung and Suha Sari and Eren Demirhan
• Companies: Pfizer, Inc. and Pfizer, Inc. and Astellas Pharma, Inc. and Pfizer, Inc. and Pfizer, Inc.
• Keywords: Surrogacy; Survival analysis; Clinical Trials; Prostate Cancer

Abstract

Background: Prostate cancer is the second most common cancer and the second leading cause of cancer death in American men. Due to many approved drugs with life extending capability, establishing an effect on OS is creating challenges for clinical trials and this leads to increased study size and duration. Identifying surrogates for OS will be beneficial for accelerating clinical development programs and will open opportunities for exploring treatment alternatives.

Methods: Three placebo-controlled randomized phase 3 clinical trials (AFFIRM, PREVAIL, Asian PREVAIL) from the enzalutamide program in metastatic castration-resistant prostate cancer were identified, and data will be collected from 3323 subjects. Two candidate endpoints for potential surrogacy for OS have been identified: time to prostate-specific antigen progression, and radiographic progression-free survival. Surrogacy analysis will be based on the correlation approach proposed by Burzykowski et al and Buyse et al using bivariate copula models with individual- and trial-level surrogacy criteria.

Results and Conclusion: Results and conclusion will be discussed during the presentation.