Phase III trial results presented today show a drug developed by British scientists can significantly extend overall survival for men with advanced prostate cancer.
Abiraterone acetate is a pill discovered at The Institute of Cancer Research (ICR) that treats aggressive prostate cancer, which each year kills 10,000 men in the UK.
Chief Investigator Dr Johann de Bono from the ICR and the Royal Marsden NHS Foundation Trust says the study results, which he presented today at the European Society for Medical Oncology Congress in Milan, Italy, may lead to a change in the way doctors treat these patients.
“This is extremely exciting because men with this aggressive type of prostate cancer currently have very few treatment options and a poor prognosis,” says Dr de Bono, who is funded by Cancer Research UK. “Around one man in the UK dies every hour from this disease, so the news that abiraterone acetate may extend survival with manageable side-effects will be incredibly important to men with prostate cancer and their families.”
The randomised Phase III trial, 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 abiraterone acetate plus the steroid prednisone was 14.8 months, compared to 10.9 months for the 398 patients who received the steroid and a placebo.
When compared to the placebo group, patients on abiraterone acetate were more likely to experience a significant drop in their prostate specific antigen (PSA) levels, the standard measure of prostate cancer activity. X-rays showed mean time for tumour growth among the treatment group was halted for longer, and, on average, men taking abiraterone acetate also had more time before their PSA level started to rise again.
Doctors reported patients taking abiraterone acetate generally did not experience some of the unpleasant side-effects associated with chemotherapy. Patients in the abiraterone acetate group did experience more minerlocorticoid-related side effects than those in the placebo group, but these were usually amenable to medical management.
Abiraterone acetate is an investigational compound discovered by Professor Mike Jarman and his colleagues in what is now the Cancer Research UK Cancer Therapeutics Unit at the ICR, and is licensed from BTG International LTD to Janssen.
Prostate cancer growth is fuelled by the male hormone testosterone, and in its aggressive form can produce its own supply. Abiraterone acetate is a targeted therapy designed to block an enzyme involved in the synthesis of testosterone.
Harpal Kumar, Cancer Research UK’s chief executive, said: “These results show abiraterone can make a real difference for men with this type of disease. It’s certainly a significant improvement on what might be expected for men with such advanced prostate cancer.”
Based on results of a prespecified 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.
ICR Chief Executive Professor Peter Rigby said: “We are very proud that a drug discovered at The Institute of Cancer Research may give men with advanced prostate cancer a new treatment option for managing their condition and improving survival.”
Prostate cancer has overtaken lung cancer to become the most common cancer in men. One man dies of prostate cancer in the UK every hour, and more than 35,000 men are diagnosed with the disease every year. Prostate cancer is considered to be advanced once it has spread beyond the prostate region.
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.
Abiraterone was discovered at the ICR in research supported by grants from Cancer Research Campaign (now Cancer Research UK), the Medical Research Council (MRC) and BTG. Subsequent patient trials and further research on abiraterone was supported by Cougar Biotechnology Inc. / Janssen Pharmaceutical Companies, Cancer Research UK, Experimental Cancer Medicine Centre, the MRC, BTG, Prostate Cancer Foundation, Prostate Cancer Research Foundation, Prostate Cancer Charity, the ICR and The Royal Marsden.
The Institute of Cancer Research (ICR)
