Ovarian cancer drug olaparib slows recurrence and cuts deaths

A drug to treat ovarian cancer has shown promising results in a clinical trial, delaying signs of relapse and reducing chances of death. 

The phase III clinical trial, funded by AstraZeneca and Merck, assessed the efficacy of olaparib in 391 women with advanced ovarian cancer who had a BRCA gene mutation. Of these, 260 women treated with olaparib had a 70 percent reduced risk of cancer recurrence or death, compared with patients who did not receive the drug.

'The most exciting finding is that more than half the patients on the olaparib arm have not relapsed with a minimum of three years of follow-up,' said Professor Charlie Gourley, director of ovarian cancer research at the University of Edinburgh, which ran the British arm of the international trial.

'This is unprecedented and raises the possibility that a number of these patients may be cured, although longer follow-up of patients is required before we can definitively draw this conclusion.'

The study, published in The New England Journal of Medicine, showed that olaparib can be used as a maintenance and preventive therapy in patients who had already had chemotherapy or surgery, but showed no signs of disease relapse.

The majority of patients with ovarian cancer have no evidence of disease after ordinary treatment with surgery and chemotherapy, however approximately 70 percent have a relapse within three years. Recurrent ovarian cancer is typically incurable and represents a global unmet need, with around 7300 new cases every year in the UK.

Olaparib belongs to the class of PARP inhibitor drugs, so called because they block PARP proteins in cancer cells. PARP proteins prevent DNA damage in tumour cells carrying a BRCA mutation. Olaparib interferes with PARP molecules, causing an accumulation of DNA errors in cancer cells, ultimately leading to death of these cells. The drug is already approved in the USA and in Europe to treat advanced ovarian cancer that has returned after chemotherapy.

Dr Shibani Nicum, an oncologist at Oxford University Hospitals who was not involved in the study, said the findings were extremely important for women with newly diagnosed ovarian cancer and a BRCA mutation, 'raising the possibility of curing some women'.

Dr Nicum added: 'The future will be exciting as we determine how we might use olaparib and other PARP inhibitors to benefit a wider group of women.'