Ovarian cancer drug delays relapse
Experts from the University of Edinburgh’s Cancer Research UK Edinburgh Centre led the UK arm of an important ovarian cancer drug study: October 2018
Women with a type of ovarian cancer caused by mutations in their DNA could be helped by a drug that slows progression of the disease.
A breakthrough clinical trial has found the treatment can delay relapse of the disease by at least three years in women with advanced ovarian cancer caused by mutations in the BRCA gene.
Experts say the effects could be greater, as many of the women involved in the study – which began in 2013 – have not yet relapsed.
The drug – called olaparib – is already used to treat women whose advanced ovarian cancer has returned. This study shows the treatment could help newly diagnosed women with a BRCA mutation to avoid relapse.
Standard treatment for ovarian cancer involves surgery and chemotherapy. Most patients have no evidence of disease after treatment, however, around 70 per cent will relapse within three years.
Ovarian cancer is typically incurable once it returns. Patients go on to receive several types of treatment – including olaparib – but over time the interval between their relapses becomes shorter and shorter.
The trial – called SOLO1 – involved patients in 15 countries and was led by the Stephenson Oklahoma Cancer Center in the USA. Experts from the University of Edinburgh’s Cancer Research UK Edinburgh Centre led the UK arm of the study.
Some 391 women took part in the study, of which 260 received olaparib and 130 were given a dummy pill. Each had been newly diagnosed with advanced ovarian cancer caused by BRCA mutations.
They had already received standard treatment that had either completely or partially eliminated their cancer.
After three years, around two thirds of women who received olaparib had not yet relapsed compared with around one third of women who received the placebo.
Overall, the treatment was associated with a 70 per cent reduction in risk of disease progression or death.
Olaparib, also known as Lynparza, is a type of drug called a PARP inhibitor. This class of drugs works by blocking a molecule called PARP inside cells.
Cancer cells with a change in the BRCA gene rely on PARP to keep their DNA healthy. When olaparib stops PARP from repairing DNA damage, the cancer cells die.
The findings are published in the New England Journal of Medicine and are being presented at the European Society for Medical Oncology Annual Congress in Munich.
Olaparib is produced by AstraZeneca and Merck, who also funded the trial.
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. 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.
Article in the New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMoa1810858
Information about ovarian cancer: http://www.cancerresearchuk.org/about-cancer/ovarian-cancer
Information about Olaparib: https://bnf.nice.org.uk/drug/olaparib.html
Prof Charlie Gourley’s group web page: https://www.ed.ac.uk/cancer-centre/research/gourley-group