By inhibiting CYP17 (17alpha-hydroxylase/C17,20-lyase), abiraterone blocks the synthesis of testosterone in the adrenal glands and testes, as well as in the prostate tumour itself.1
Approval of abiraterone was based on a randomised, double-blind phase 3 trial in 1195 men with metastatic prostate cancer who had previously received docetaxel. In this trial, men who were given abiraterone 1g daily, plus low-dose prednisone or prednisolone, lived for a median of 14.8 months compared with 10.9 months for men taking placebo plus prednisolone or prednisone.1 This difference translated into a 35.4% reduction in the risk of death with abiraterone compared with placebo (95% CI 23–46%; p<0.001).2
The proportion of patients who experienced a 30% reduction in the worst pain intensity was also significantly greater with abiraterone than placebo (44% vs 27%; p=0.0002).
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Further information: Janssen-Cilag