Hundreds of women could benefit from ovarian cancer drug pairing that doubles chance of remission

Hundreds of women with ovarian cancer could benefit from a new drug combination found to be twice as effective as existing treatments.

Low-grade serous ovarian cancer (LGSOC) disproportionately affects younger women, is notoriously difficult to detect and has few effective treatment options.

Researchers from the Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London, conducted the trial, which saw tumours shrink significantly in almost half (45 per cent) of those given avutometinib alongside defactinib.

Experts said early results, presented at the American Society of Clinical Oncology conference in Chicago, were ‘fantastic news’ and could change treatment for patients. 

Around 700 women in the UK are diagnosed with LGSOC annually – most between the ages of 40 and 60. Symptoms – which include bloating, changes in bowel movements, and severe back, pelvic and stomach pain – can be misdiagnosed, leading the cancer to be caught late.

Symptoms  of ovarian cancer – which include bloating, changes in bowel movements, and severe back, pelvic and stomach pain – can be misdiagnosed, leading cancer to be caught late

Treatment often involves surgery followed by chemotherapy and hormone therapy. But response rates are typically poor, with the most effective drug having only a 26 per cent success rate.

Avutometinib works by blocking proteins that help control cancer growth and survival. Studies have shown it can become ineffective over time, with tumours developing resistance to treatment.

However, when combined with defactinib – which is designed to combat a protein that encourages drug resistance – avutometinib works more efficiently.

Patients were deemed to have responded to the treatment if their total tumour dimensions shrank by at least 30 per cent.

Study co-author Dr Kathleen Moore, of the Stephenson Cancer Center in Oklahoma, said the large increase in response rates for the new drug combination was ‘very exciting’.

She said: ‘The beauty of the combination is you’re outsmarting two ways these tumours become resistant and using a drug that’s more effective. This response rate is the best reported for any medicine in LGSOC.’

The findings may be particularly important for patients whose cancer cannot be removed by surgery, who currently have few other options. Results of the drug combination, which was given to 29 women, were particularly promising in those with the KRAS gene mutation, with six in ten seeing their tumours shrink.

Meanwhile, nearly a third (29 per cent) without the mutation also had an encouraging response – an improvement on standard treatment.

Those previously given other types of therapies also saw their cancer shrink with treatment with the drug combination, according to interim results. 

Dr Susana Banerjee, consultant medical oncologist at the Royal Marsden, who led the research, said: ‘These initial results could be fantastic news for women.’