A recent study has suggested that a new three-drug combination could extend the life of women with a common form of aggressive breast cancer. The study included 325 patients from 28 countries and found that the treatment more than doubled the time before the cancer progressed or worsened. This combination may become the preferred option for women with PIK3CA-mutated hormone receptor positive (HR+) human epidermal growth factor receptor 2 negative (HER2-) breast cancer. The researchers used a liquid biopsy to test for the PIK3CA mutation, and the three-drug combination included palbociclib, inavolisib, and fulvestrant.
The trial also showed that the three-drug therapy delayed disease progression and the need for chemotherapy compared to the placebo group. While the combined therapy has not been approved in the UK, the combination of palbociclib and fulvestrant has been available for certain types of breast cancer patients since 2022.
Lead author Nick Turner noted that the inavolisib-based therapy not only helped patients live longer but also doubled the time before their cancer progressed, delaying the need for chemotherapy. The results of the trial were published in the New England Journal of Medicine and presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
About 55,000 women are diagnosed with breast cancer in the UK each year, with the majority having HR+, HER2- breast cancer. PIK3CA mutations are present in 35-40% of HR+ breast cancers. Prof Kristian Helin from the Institute of Cancer Research, London, highlighted the effectiveness of the combination therapy and its tolerability by patients. Dr Simon Vincent from Breast Cancer Now called the findings a significant breakthrough.
