News Feature | October 2, 2014

Janssen-Cilag Posts Phase 3 Data For Zytiga In Prostate Cancer

By Estel Grace Masangkay

Janssen-Cilag International reported positive data from the final analysis of its Phase 3 trial investigating Zytiga in male patients with metastatic castration-resistant prostate cancer (mCPRPC) who have not yet undergone chemotherapy.

Zytiga inhibits the hepatic drug-metabolizing enzyme CYP2D6, which plays a crucial role in the production of androgens. Androgens are hormones that promote growth and maintenance of normal male sex characteristics, but which can also drive tumor growth in prostate cancer. Zytiga inhibits androgen production at all three sources, namely the adrenal glands, testes, and in the tumor itself. The drug received approval from the U.S. Food and Drug Administration (FDA) in 2011 as treatment for mCRPC and in over 90 countries since.

In the international, placebo controlled, double blind, randomized Phase 3 COU-AA-302 study, the combination of Zytiga and prednisone significantly lengthened overall survival versus an active control of placebo plus prednisone. The combo therapy also achieved a 19 percent reduction in mortality risk in patients with mCRPC after a median follow-up study of 49 months.

“OS is particularly noteworthy in COU-AA-302, because 67 percent of men in the Zytiga plus prednisone arm and 80 percent in the control arm received subsequent therapy. This includes 44 percent of men in the control arm who subsequently received Zytiga plus prednisone,” said Charles Ryan, Professor of Clinical Medicine of Urology at the University of California in San Francisco, and lead investigator of the COU-AA-302 study. Dr. Ryan added that the final analysis confirms a consistent safety profile for the combination therapy.

Dr. Peter Lebowitz, Global Therapeutic Area Head of Oncology at Janssen, said that the company is pleased to advance the development of new treatments for prostate cancer. “In the last few years, we've entered a new era in prostate cancer treatment, with non-chemotherapy based treatment regimens and medicines based on an increasingly sophisticated understanding of the mechanism of disease.”

The company presented the results of the final analysis at the European Society for Medical Oncology (ESMO) 2014 Congress held in Madrid, Spain.

In addition to data for Zytiga and prednisone, Janssen also presented positive Phase 2 results for ARN-509. The investigational drug is currently undergoing Phase 3 development as treatment for high-risk non-metastatic castration-resistant prostate cancer (M0-CRPC). Janssen also shared clinical data for ARN-509 at the American Society of Clinical Oncology (ASCO) this May.