22-05-2025
Fresh calls for health chiefs to give breakthrough breast cancer drug green light as pivotal trial shows it boosts survival
A three-drug 'breakthrough' treatment for aggressive, advanced breast cancer can prolong survival by a quarter, a pivotal trial has found.
Thousands of women could benefit after tests showed the method was more effective than the current NHS offering.
Scientists found the drug, Inavolisib, taken in combination with two other medications saw survival prolonged to just under three years, compared with a little over two.
Researchers have hailed the results as potentially transformative for those with PIK3CA-mutated HR+/HER2- breast cancer—a common form of the disease triggered by a mutation on the PIK3CA gene.
Last year medicines regulator the Food and Drug Administration approved the new therapy combination in the US and it was hoped that it would become the standard of care for women with this form of the disease.
In the UK, however, NHS watchdog the National Institute for Health and Care Excellence (NICE) has not yet granted Inavolisib approval.
Professor Nicholas Turner, from The Institute of Cancer Research, London and the Royal Marsden NHS Foundation Trust, led the major trial into the drug, which was developed following years of research by the institute.
He said: 'The study was designed to address a need for more potent and tolerable therapies for PIK3CA-mutated HR+/HER2- breast cancer.
'The trial findings support an inavolisib-based treatment as an emerging new standard of care that helps people live longer, as well as substantially improving how long treatment works.'
The drug, which is also known as Itovebi and made by Roche, works by blocking the action of the PIK3CA gene mutation that drives cancer cells to multiply.
It therefore helps to slow or stop the spread of cancer cells.
In the trial, 164 patients were given the available treatment of palbociclib, a cancer growth blocker, and fulvestrant, a hormone therapy.
The other 161 were also given new drug inavolisib.
Researchers found average overall survival stood at around 34 months for those on the three-drug treatment.
For those on the two, it was just 27 months.
Overall, the inavolisib combination reduced the risk of death by 33 per cent for patients, they added.
Meanwhile, the proportion of patients whose tumors shrank by more than 30 per cent in response to treatment was 63 per cent for patients in the inavolisib group versus 28 per cent in the placebo group.
A greater proportion of patients on the three-drug treatment discontinued treatment due to side effects (6.8 per cent), however, compared to the two-drug group (0.6 per cent).
The findings will be presented in full next week at the American Society for Clinical Oncology (ASCO) conference in Chicago.
Professor Jane Lowe Meisel, an expert in medical oncology at Emory University in Atlanta and ASCO breast cancer expert, said: 'The trial has identified a targeted treatment regimen that meaningfully improves survival in patients with untreated PIK3CA-mutated HR+/HER2- breast cancer—a big step forward for these patients.
'This study illustrates the importance of genomic testing at the time of diagnosis of hormone receptor-positive metastatic breast cancer, so that patients with PIK3CA mutations who qualify for this approach can be readily identified.'
One in seven women in the UK are diagnosed with breast cancer in their lifetime — around 56,000 a year — making it the most common cancer in the UK.
The figure stands at roughly 300,000 annually in the US.
HR+/HER2- breast cancer is the most common subtype of breast cancer, accounting for about 70 per cent of breast cancers.
Research has found that around 40 per cent of people with HR+/HER2- have a mutation in the PIK3CA gene.
