AstraZeneca and Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced positive results from the Phase 3 PROpel trial, in which LYNPARZA in combination with abiraterone and prednisone demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of radiographic progression-free survival (rPFS) versus abiraterone plus prednisone as a first-line treatment for men with metastatic castration-resistant prostate cancer (mCRPC) with or without homologous recombination repair (HRR) gene mutations.
At a planned interim analysis, the Independent Data Monitoring Committee concluded that the trial met the primary endpoint of rPFS in men with mCRPC who had not received treatment in the first-line setting, including new hormonal agents (NHAs) or chemotherapy. The trial also showed a trend at this interim analysis towards improved overall survival (OS). However, the OS data are still immature, and the trial will continue to assess OS as a key secondary endpoint. The safety and tolerability were consistent with the known profiles of each medicine and will continue to be assessed.
Globally, prostate cancer is the second most common cancer in men, with an estimated 1.4 million patients diagnosed worldwide in 2020. Approximately 10-20% of men with advanced prostate cancer are estimated to develop CRPC within five years, and at least 84% of these men may develop metastases at the time of CRPC diagnosis.
Susan Galbraith, executive vice president, oncology R&D, AstraZeneca, said, “Today, men with metastatic castration-resistant prostate cancer have limited options in the first-line setting, and sadly often the disease progresses after initial treatment with current standards of care. These exciting results demonstrate the potential for LYNPARZA with abiraterone to become a new first-line option for these patients regardless of their biomarker status and may help reach a broad population of patients living with this aggressive disease. We look forward to discussing the results with global health authorities as soon as possible.”
Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories, said, “We are encouraged by the PROpel results and the clinical benefit LYNPARZA in combination with abiraterone demonstrated versus abiraterone as a potential first-line treatment option for men with metastatic castration-resistant prostate cancer. These data build on Merck and AstraZeneca’s commitment to bring LYNPARZA to earlier lines of treatment and to more patients with advanced prostate cancer.”
The data will be presented at an upcoming medical meeting.