A drug that targets genetic mutations in ovarian cancer has been found to work in men with prostate cancer with similar mutations, according to a new study.
Researchers from the Institute of Cancer Research, London, used the drug olaparib to treat men with incurable metastatic prostate cancer. They found that it was particularly effective in men whose tumours had DNA-repair mutations similar to those found in some breast and ovarian cancers.
'Our trial marks a significant step forward in the treatment of prostate cancer,' said Professor Johann de Bono, chief investigator for the study, which was published in the New England Journal of Medicine. 'I hope it won't be long before we are using olaparib in the clinic to treat prostate cancer.'
Previous studies showed that oliparib can be effective against ovarian cancers involving DNA-repair mutations. In this trial, 49 patients who had metastatic prostate cancer despite extensive treatment were evaluated. They were all treated with olaparib and their tumours were analysed for mutations in DNA-repair genes.
Sixteen patients were found to have DNA-repair mutations, including seven with the BRCA2 mutation, which is commonly associated with breast and ovarian cancers. Of these, 14 patients responded to the drug compared with just two out of 33 patients without DNA-repair mutations. All the patients with the BRCA2 mutation responded to the drug.
The use of genetic biomarkers to plan treatment was described as a 'game changer' by Dr Ganesh Raj, Associate Professor of Urology at the University of Texas, Dallas, who was not involved in the study. He told the Pharmaceutical Journal: 'These findings are truly remarkable given the extensive amount of therapy that these patients have already received.'
Dr Emma Hall, study co-leader, emphasised the need for further research to confirm these findings: 'The next trial includes only men with these mutations in their tumours, with the aim of proving that olaparib is highly effective for them.'
Professor William Nelson, Director of the Sidney Kimmel Comprehensive Cancer Center in Baltimore, Maryland, who was not involved in the study, said: 'We can identify prostate cancer patients who will benefit from drugs like olaparib, and also help men and their families better understand their genetic risk of metastatic prostate cancer, just as women with BRCA mutations do for breast and ovarian cancer.'