OncoGenex And Teva's Prostate Cancer Drug Regimen Fails In Trial

OncoGenex Pharmaceuticals and Teva Pharmaceutical Industries announced that the Phase III SYNERGY trial assessing their investigational therapy in prostate cancer failed to meet its primary endpoint.

The open-label, randomized, two-arm study compared the combination of custirsen and standard first-line docetaxel/prednisone therapy to docetaxel/prednisone alone in men with metastatic castrate-resistant prostate cancer (CRPC). Top-survival results indicated that the addition of custirsen to standard first-line therapy docetaxel/prednisone did not result in a statistically significant improvement in overall survival in men with metastatic CRPC, compared to standard treatment alone.

Prostate cancer is the second leading cause of death in male patients in the U.S. after lung cancer. According to the American Cancer Society, about 233,000 new cases of prostate cancer will be diagnosed this year. Approximately 28,480 patients will die from the disease in 2014.

Michael Hayden, MD, president of global R&D and CSO at Teva Pharmaceutical Industries, said, “We are disappointed with these results. Addressing treatment resistance is critical in the fight against cancer. We are working with OncoGenex to more fully understand these data.”

Custirsen is an investigational drug designed to block the production of clusterin, a protein that may play a fundamental part in cancer cell survival and treatment resistance. Clusterin is observed to be unregulated in tumor cells in response to treatment such as chemotherapy, hormone ablation, and radiation therapy. The protein is also found to be overexpressed in several cancers including prostate, lung, bladder, and breast. Faster rates of cancer progression, shorter survival duration, and treatment resistance have all been tied to increased production of clusterin.

Through its inhibition of clusterin, custirsen is intended to alter tumor dynamics, slow tumor growth and resistance to adjunct treatments to extend survival and other therapy benefits. The drug was administered to 294 patients with various types of cancers as part of Phase I and Phase II clinical trials.

The company said full efficacy and safety data of the SYNERGY trial will be presented at a future scientific conference.