Abiraterone

Clinical studies

The first study run at the Royal Marsden Hospital, London, in patients who had not received chemotherapy reported that abiraterone acetate induced decline in prostate specific antigen in up to 70% of patients as well as radiological shrinkage of tumors, symptom improvement, normalization of lactate dehydrogenase. However others have cautioned that it is too early to know whether abiraterone treatment will have long term benefit. Results of two Phase II trials indicate that abiraterone may reduce prostate specific antigen (PSA) levels, as well as shrink tumors. On average, progression-free survival was prolonged by 161 days in patients which had been treated with chemotherapy, and by 236 days in chemotherapy naive patients. A Phase III trial in subjects previously treated with docetaxel started in 2008 and is now closed to accrual. A placebo-randomized phase III clincal trial in patients with castration-refractory prostate cancer who are chemotherapy-naive opened to accrual in April 2009.