Positive high-level results from the PROpel Phase III trial have shown that AstraZeneca and MSD’s Lynparza (olaparib), in combination with abiraterone, demonstrated a significant improvement in radiographic progression-free survival (rPFS) versus standard-of-care abiraterone as a 1st-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 (IDMC) concluded that the trial met the primary endpoint of rPFS in men with mCRPC who had not received treatment in the 1st-line setting including with new hormonal agents (NHAs) or chemotherapy.

The first PARP inhibitor to demonstrate clinical benefit in combination with a new hormonal agent in this setting, the trial also showed a trend at this interim analysis towards improved overall survival (OS). However, the trial will continue to assess OS as a key secondary endpoint.

Susan Galbraith, Executive Vice President, Oncology R&D, said: “Today, men with metastatic castration-resistant prostate cancer have limited options in the 1st-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 1st-line option for patients regardless of their biomarker status and 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, MSD Research Laboratories, said: “We are encouraged by the PROpel results and the clinical benefit Lynparza in combination with abiraterone demonstrated versus abiraterone alone as a 1st-line treatment option for men with metastatic castration-resistant prostate cancer. Today’s results build on MSD and AstraZeneca’s commitment to bring Lynparza earlier in lines of treatment and to more patients with advanced prostate cancer.”