A three-drug combination targeting aggressive advanced breast cancer could potentially double the amount of time patients live without the disease progressing, a trial has found.
Researchers hailed the “huge breakthrough” as potentially “transformative” for those with a common form of breast cancer.
A mutation in the gene known as PIK3CA causes cells to divide and replicate uncontrollably, leading to the development of PIK3CA-mutated hormone receptor positive (HR+) human epidermal growth factor receptor 2 negative (HER2-) breast cancer.
The study, known as INAVO120 and published in the The New England Journal of Medicine, included 325 patients from across 28 countries.
More than half had cancer that had spread to three or more organs, while more than 80% had already had chemotherapy.
Of the total, some 161 patients were given the three-drug combination, which comprised two targeted drugs – palbociclib, a type of cancer growth blocker, and a new drug called inavolisib, which blocks the activity of the PI3K protein – as well as the hormone therapy fulvestrant.
The placebo group, which included 164 patients, were given a placebo plus palbociclib and fulvestrant.
Researchers found the three-drug therapy delayed disease progression by an average of 15 months compared with 7.3 months in the placebo group.