FDA Expands Use of Abiraterone (Zytiga) for Late-Stage Prostate Cancer
Drug can now be used before treatment with chemotherapy (Dec. 10)
The FDA has expanded the approved use of abiraterone acetate (Zytiga, Janssen Biotech) to treat men with late-stage (metastatic) castration-resistant prostate cancer prior to receiving chemotherapy.
The agency initially approved Zytiga (abiraterone) in April 2011 for use in patients whose prostate cancer progressed after treatment with docetaxel, a chemotherapy drug. Abiraterone decreases the production of testosterone.
In prostate cancer, testosterone stimulates prostate tumors to grow. Drugs or surgery is used to reduce testosterone production or to block testosterone’s effects. Some men have castration-resistant prostate cancer, which means that the cancer cells continue to grow even with low levels of testosterone.
The safety and effectiveness of abiraterone for its expanded use were established in a clinical study of 1,088 men with late-stage, castration-resistant prostate cancer who had not received chemotherapy. The participants received either abiraterone or placebo in combination with prednisone. The study was designed to measure overall survival (OS) and radiographic progression-free survival (rPFS).
Patients treated with abiraterone had a median OS of 35.3 months compared with 30.1 months for those receiving placebo. The study results also showed that abiraterone improved rPFS. The median rPFS was 8.3 months in the placebo group and had not yet been reached for patients treated with abiraterone at the time of the analysis.
The most common side effects reported in those receiving abiraterone included fatigue, joint swelling or discomfort, swelling caused by fluid retention, hot flushes, diarrhea, vomiting, cough, high blood pressure, shortness of breath, urinary tract infection, and bruising.
Source: FDA; December 10, 2012.