Centocor Ortho Biotech reports that Zytiga (abiraterone acetate), an oral, once-daily medication for use in combination with prednisone for the treatment of metastatic castration-resistant prostate cancer who have received prior chemotherapy containing docetaxel has been approved by the FDA.

Zytiga is an androgen biosynthesis inhibitor that works by inhibiting the CYP17 enzyme complex, which is required for the production of androgens in the testes, adrenal glands, and at the site of the tumor.

Results of the pivotal phase III, randomized, placebo-controlled, multicenter study showed that at pre-specified interim analysis, treatment with Zytiga in combination with prednisone resulted in a 35% reduction in the risk of death (14.8 months vs. 10.9 months [hazard ratio(HR) = 0.646; 95 percent CI: 0.543, 0.768; p

The most common adverse reactions were joint swelling or discomfort, hypokalemia, edema, muscle discomfort, hot flush, diarrhea, urinary tract infection, cough, hypertension, arrhythmia, urinary frequency, nocturia, dyspepsia and upper respiratory tract infection.