The therapy delayed the need for further chemotherapy by nearly two years, providing a significant quality-of-life benefit for patients living with advanced breast cancer
A groundbreaking new combination therapy has shown significant promise in treating one of the most aggressive forms of breast cancer, offering patients longer survival, delayed disease progression, and a reprieve from the harsh effects of chemotherapy.
The treatment—consisting of two targeted drugs, inavolisib and palbociclib, combined with the hormone therapy fulvestrant—was found to improve overall survival by an average of seven months compared to standard care. It also more than doubled the time before disease progression, from 7.3 months in the control group to 17.2 months in patients receiving the new regimen.
Notably, the therapy delayed the need for further chemotherapy by nearly two years, providing a significant quality-of-life benefit for patients living with advanced breast cancer. These findings, presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago and published in the New England Journal of Medicine, stem from the international INAVO120 clinical trial, funded by Roche. The study enrolled 325 patients from 28 countries, including the US, UK, Australia, and Brazil. The trial specifically targeted patients with PIK3CA-mutated, hormone receptor-positive (HR+), HER2-negative metastatic breast cancer—a subtype affecting about 70% of breast cancer patients. Mutations in the PIK3CA gene occur in 35-40% of these cases and are associated with tumor growth and resistance to treatment.
Dr. Jane Lowe Meisel, Co-Director of Breast Medical Oncology at Emory University’s Winship Cancer Institute, called the findings a “big step forward,” saying the trial “identified a targeted treatment regimen that meaningfully improves survival.”
In the trial, tumor shrinkage was observed in 62.7% of patients receiving the triple therapy, compared with just 28% in the control group. The therapy was generally well tolerated, with only a small number of patients discontinuing due to side effects. Dr. Simon Vincent, Director of Research at Breast Cancer Now, hailed the results as a “significant breakthrough,” while Cancer Research UK’s Dr. Nisharnthi Duggan emphasized the importance of treatments that not only extend life but also improve its quality. “This therapy gave people more time with loved ones and delayed the need for chemotherapy,” she noted.
Patients in the study were tested using liquid biopsy blood tests to confirm the presence of PIK3CA mutations before being randomly assigned to receive the new therapy or a standard regimen plus a placebo.
Professor Nick Turner, who led the UK arm of the study, summarized the impact: “This inavolisib-based therapy not only helped patients live longer, but it also more than doubled the time before their cancer worsened. Most importantly, it delayed the need for chemotherapy—something patients fear and want to postpone as long as possible.”
