Olaparib regimen extends radiographic PFS in metastatic prostate cancer
A randomized phase 3 study that assessed the addition of olaparib to abiraterone as first-line treatment for men with metastatic castration-resistant prostate cancer met its primary endpoint, according to the agent’s manufacturer.
Researchers reported a statistically significant improvement in radiographic PFS among men assigned the combination regardless of homologous recombination repair (HRR) gene mutation status.
Olaparib (Lynparza; AstraZeneca, Merck) is a poly(ADP-ribose) polymerase (PARP) inhibitor approved in the United States for treatment of men with HRR-mutated metastatic castration-resistant prostate cancer. It also is approved to treat certain patients with ovarian, pancreatic or breast cancers.
The randomized, phase 3 PROpel trial assessed the efficacy and safety of olaparib vs. placebo added to standard abiraterone for men with metastatic castration-resistant prostate cancer who had not received prior chemotherapy or new hormonal agents. Men in both groups also received prednisone or prednisolone twice daily.
Researchers enrolled men with or without HRR gene mutations. All men had ECOG performance status of 0 or 1. Men previously treated with docetaxel during a prior stage of disease were eligible; however, those who received prior abiraterone were excluded.
Results of an interim analysis showed the study met its primary endpoint of radiographic PFS as determined by an independent data monitoring committee.
Results also showed a trend toward improved OS — a secondary endpoint — however, these data remained immature.
“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,” Susan Galbraith, executive vice president for oncology research and development with AstraZeneca, said in a company-issued press release. “These exciting results demonstrate the potential for Lynparza with abiraterone to become a new first-line option for patients regardless of their biomarker status and reach a broad population of patients living with this aggressive disease.”
The safety and tolerability of the olaparib-abiraterone combination appeared consistent with the known safety profiles of each agent, according to researchers.
Complete results from the PROpel trial will be submitted for presentation at a medical meeting.