A new combination of drugs has been shown to shrink ovarian cancer tumours in women suffering a form of the disease usually resistant to treatment.
The two drugs, which block the signals that cancer cells need to grow, could become a new treatment option.
The treatment shrank tumours significantly in 46 per cent of patients, findings of a small Phase 1 trial carried out by the Institute of Cancer Research and The Royal Marsden NHS Foundation Trust show.
“This study has turned a deep understanding of how cancer fuels its growth and develops resistance into a highly targeted treatment for patients who currently have few treatment options,” said ICR chief executive Prof Kristian Helin.
Larger trials will need to be carried out to fully determine the effectiveness of the new combination, but scientists said they were “delighted” at its potential to be a “significant advance” in treatment options.
“We’re very hopeful that this could become the standard of care for women with low-grade serous ovarian cancer,” said Dr Susana Banerjee, team leader in women’s cancer at ICR.
The drugs, called VS-6766 and Defactinib, were tested in 25 patients with low-grade serous ovarian cancer, an uncommon form of the disease that tends to develop in younger women. Fewer than 14 per cent of patients respond to chemotherapy or hormone therapy, ICR said.
Trial results, presented at the 2021 European Society for Medical Oncology Congress, show that of the 24 patients evaluated, 46 per cent saw their tumours shrink significantly in response to the treatment.
The outcomes were even better in patients with a particular mutation, with 64 per cent who have KRAS-driven tumours seeing them shrink following treatment, the trial results show.
“Scientists have been working to develop treatments that can effectively target KRAS cancers for decades,” said Professor Helin.
“It's fantastic that early trials indicate this treatment is highly effective for this patient group, and that a phase two trial has already begun.”
The combination treatment also worked in patients who had already received an MEK inhibitor, which can cause tumours to shrink but tends to stop working as tumours develop resistance to treatment, before the study.
“I am delighted that this drug combination has worked so well in a group of patients who are in urgent need of new treatments, including those who have previously been treated with a MEK inhibitor,” said Dr Banerjee.
The researchers said tumour profiling could be used to identify which patients are most likely to benefit from the new drug combination.
They said those taking part in the trial — aged between 31 and 75 — lived an average of 23 months before their cancer progressed.