New drug improves prostate cancer survival

Results of a phase III randomised trial presented today, October 11, during the Presidential Symposium at the 35th Annual European Society for Medical Oncology (ESMO) Congress have shown that abiraterone acetate can significantly extend overall survival in men with metastic advanced prostate cancer (also known as castration resistant prostate cancer, or CRPC) by 36 per cent.

Abiraterone acetate is a novel, targeted, investigational oral androgen biosynthesis inhibitor being developed for treatment of metastatic advanced prostate cancer that has progressed after developing resistance to conventional hormonal therapies.

The investigational compound was discovered by Professor Mike Jarman and his colleagues in what is now the Cancer Research UK Cancer Therapeutics Unit at the Institute of Cancer Research (ICR). It is licensed from BTG International LTD to Janssen. 

The randomised phase III trial (COU-AA-301), funded by Janssen Pharmaceutical Companies, included 1,195 patients from 13 countries whose advanced prostate cancer had previously been treated with other available therapies, including docetaxel-based chemotherapy. Average overall survival among the 797 patients who received oral abiraterone acetate plus either of the steroids prednisone or prednisolone was 14.8 months, compared with 10.9 months for the 398 patients who received the steroid and a placebo. Treatment with abiraterone acetate reduced the risk of death by 35 per cent.

"This is extremely exciting because men with this aggressive type of prostate cancer currently have very few treatment options and a poor prognosis," said chief investigator Dr Johann de Bono from the ICR and the Royal Marsden NHS Foundation Trust, who is funded by Cancer Research UK. 

Based on results of a pre-specified interim analysis of the study, the trial's Independent Data Monitoring Committee recommended unblinding the trial and allowing anyone on the placebo arm to be offered the drug.

Janssen also now plans to file marketing applications for abiraterone acetate with regulatory authorities in the US and Europe by the end of the year. Applications in the rest of the world will follow, according to local regulatory requirements.