Breast cancer breakthrough as new drug combination stops disease in its tracks

A new drug combination could help breast cancer sufferers live up to twice as long without the disease progressing, according to new research.

Described by scientists as "potentially transformative," this breakthrough therapy could offer new hope to those affected by this challenging form of cancer.

A recent trial involved 325 patients from 28 countries, with over half experiencing cancer spread to three or more organs, and more than 80% previously undergoing chemotherapy.

Among these participants, 161 received a three-drug therapy comprising two targeted drugs, palbociclib (a cancer growth blocker) and a new drug called inavolisib, along with the hormone therapy fulvestrant.

Together, these drugs focus on three critical pathways in a type of breast cancer driven by mutations in the PIK3CA gene.

Meanwhile, a control group of 164 patients received a placebo alongside palbociclib and fulvestrant.

The trial’s findings were striking: patients on the three-drug therapy experienced an average of 15 months before disease progression, in contrast to just 7.3 months in the placebo group.

After 18 months, 46.2% of patients receiving the new combination showed no signs of disease progression, compared with only 21.1% in the placebo group.

Lead researcher Nick Turner, professor of molecular oncology at the Institute of Cancer Research, London, said: “The results show the combination significantly improves progression-free survival when given as a first treatment. It is a huge breakthrough. It could represent a transformative advance for people with this type of breast cancer.”

According to Cancer Research UK, there are over 56,000 new cases of breast cancer annually, with nearly 11,500 deaths. Roughly 70% of patients are diagnosed with HR+/HER2- breast cancer, the subtype targeted by these drugs.

Palbociclib combined with fulvestrant has been available on the NHS since 2022 for certain breast cancer cases, though the full three-drug regimen has yet to be offered in the UK, despite its recent approval in the United States.

Prof Turner added: “This new combination helps prevent the cancer becoming resistant to therapy.”

Prof Kristian Helin, chief executive of the ICR, called the findings “very encouraging.” Anne Lury, 53, who participated in the Royal Marsden’s trial, shared: “Aside from fatigue, I had minimal side effects. Although I’m now on other treatment, I wouldn’t be here if I hadn’t had the opportunity to join the trial.”