WASHINGTON -- The FDA has approved abiraterone acetate (Zytiga) for treatment of late-stage, castration-resistant prostate cancer as a combination therapy with prednisone in patients who have received prior chemotherapy with docetaxel.
Abiraterone was approved through an expedited priority review program, which the FDA uses to clear drugs that provide major advances in treatment or treat conditions for which there are no adequate therapies.
The drug is the third approved for advanced prostate cancer in a little more than a year, following the approvals of sipuleucel-T (Provenge) and cabazitaxel (Jevtana).
Abiraterone decreases the production of the protein cytochrome P450 17A1 -- which the body uses in the production of testosterone -- and thereby curbs cancer cell growth, according to an FDA statement.
Approval was based on a clinical trial of 1,195 patients with late-stage, castration-resistant prostate cancer who had undergone prior docetaxel chemotherapy. Patients were randomized to abiraterone once a day and prednisone twice daily, or to both placebo and prednisone twice daily.
Those in the active treatment group had a median overall survival of 14.8 months, versus 10.9 months for those in the placebo group.
Adverse events include joint swelling and discomfort, low levels of blood potassium, fluid retention, muscle discomfort, hot flashes, diarrhea, urinary tract infection, cough, hypertension, heartbeat disorders, urinary frequency, increased nocturnal urination, upset stomach, and upper respiratory tract infection.
Abiraterone is manufactured by Johnson & Johnson subsidiary Centocor Ortho Biotech.