Zytiga Approved by FDA for Late-Stage Prostate Cancer
Yesterday, the U.S. Food and Drug Administration approved Zytiga (abiraterone acetate) in combination with prednisone to treat patients with late-stage castration-resistant prostate cancer who have received prior chemotherapy.
The application was reviewed under the FDA’s priority review program, which provides for an expedited six-month review for drugs that may offer major advances in treatment, or provide a treatment when no adequate therapy exists. Zytiga is being approved ahead of the product’s June 20, 2011 regulatory goal date.
Prostate cancer is the most common non-skin cancer among men. According to figures from the American Cancer Society, there were approximately 217,730 new cases of prostate cancer in 2010 and nearly 32,050 deaths.
Prostate cancer is the second leading cause of cancer death in men, behind only lung cancer. One man in 6 will get prostate cancer during his lifetime. And one man in 36 will die of this disease. More than 2 million men in the United States who have had prostate cancer at some point are still alive today.
Late-stage prostate cancers have metastasized. When prostate cancer spreads, it often goes to the bones first. It also spreads via the lymphatic system.
“Zytiga prolonged the lives of men with late-stage prostate cancer who had received prior treatments and had few available therapeutic options,” said Richard Pazdur, M.D., director of the Office of Oncology Drug Products in the FDA’s Center for Drug Evaluation and Research.
Zytiga’s safety and effectiveness were established in a clinical study of 1,195 patients with late-stage castration-resistant prostate cancer who had received prior treatment with docetaxel chemotherapy. Patients received either Zytiga once daily in combination with prednisone two times a day or a placebo (sugar pill) twice daily in combination with prednisone.
The study was designed to measure overall survival, the length of time from when the treatment started until a patient's death. Patients who received the Zytiga and prednisone combination had a median overall survival of 14.8 months compared to 10.9 months for patients receiving the placebo and prednisone combination.
The most commonly reported side effects in patients receiving Zytiga included joint swelling or discomfort, low levels of potassium in the blood, fluid retention (usually of the legs and feet), muscle discomfort, hot flashes, diarrhea, urinary tract infection, cough, high blood pressure, heartbeat disorders, urinary frequency, increased nighttime urination, upset stomach or indigestion and upper respiratory tract infection.
Zytiga is marketed by Horsham, Pa.-based Centocor Ortho Biotech, Inc.