Astellas Pharma and Pfizer have amended the protocol for the registrational PROSPER trial to test the efficacy and safety of Xtandi in patients with non-metastatic (M0) Castration-Resistant Prostate Cancer (CRPC).
The companies said the primary endpoint will remain the same, and that is metastasis-free survival (MFS). The main purpose of the amendment is to revise the plan for the analyses of the primary and several secondary endpoints, which allows for a reduction in the target sample size to approximately 1,440, from 1,560 patients. The companies now anticipate PROSPER top-line results will be disclosed later this year. Previously the expected primary completion date for PROSPER was June 2019.
“XTANDI is already a standard of care for men worldwide fighting metastatic castration-resistant prostate cancer, but we are continually looking to evaluate this medicine for men facing earlier stage disease,” said Steven Benner, from oncology development of Astellas. He added that by amending the protocol for PROSPER, evaluation of the data in the area of medical need should be accelerated.
“PROSPER is one of a number of large, randomized trials in our robust, registration-focused development program, where we are evaluating enzalutamide in different prostate cancer populations, including men with earlier stages of the disease,” said Mace Rothenberg, chief development officer, Oncology, Pfizer Global Product Development.
“We look forward to building upon the extensive body of clinical evidence that has been generated over the past five years and established XTANDI as a standard of care for men with metastatic CRPC.”
XTANDI is approved by the U.S. Food and Drug Administration for the treatment of patients with metastatic CRPC, based on clinical studies showing statistically significant overall survival benefit versus placebo.