Chicago: A new triple therapy for aggressive, advanced breast cancer has shown the potential to slow disease progression, delay further chemotherapy, and extend patient survival, as revealed by recent research.
According to Emirates News Agency, the combination treatment comprises two targeted drugs, inavolisib and palbociclib, along with the hormone therapy fulvestrant. This regimen improved overall survival by an average of seven months compared to the control group, who received only palbociclib and fulvestrant. Furthermore, the therapy delayed disease progression by an average of 17.2 months, compared to 7.3 months in the control group. Patients treated with inavolisib also postponed subsequent chemotherapy by nearly two years longer than those in the control group.
The study, funded by Roche, was presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago and published in the New England Journal of Medicine. It involved 325 patients from 28 countries, including the US, UK, Australia, Singapore, Brazil, France, and Germany.
Experts highlighted the potential of the triple therapy for targeting PIK3CA-mutated HR+, HER2- breast cancer, a prevalent form of the disease. Around 70 percent of patients have HR+, HER2- breast cancer, with PIK3CA mutations found in 35 to 40 percent of these cases, contributing to tumor growth, disease progression, and treatment resistance.
Dr. Jane Lowe Meisel, Co-Director of Breast Medical Oncology at Winship Cancer Institute of Emory University and an ASCO expert in breast cancer, remarked, "The INAVO120 trial has identified a targeted treatment regimen that meaningfully improves survival in patients with untreated PIK3CA-mutated hormone receptor-positive metastatic breast cancer - a big step forward for these patients."
The study also revealed a significant reduction in cancer growth in about 62.7 percent of patients receiving the triple therapy, compared to 28 percent in the control group. Dr. Simon Vincent, Director of Research at Breast Cancer Now, described the findings as a "significant breakthrough."
Dr. Nisharnthi Duggan, a research information manager at Cancer Research UK, noted, "The trial showed that adding inavolisib to targeted treatment plans improved survival. On top of this, it also delayed the progression of people's cancer and the need for chemotherapy, which could improve quality of life."
In the trial, more than half of the patients had disease spread to three or more organs. Researchers used circulating tumor DNA (ctDNA) liquid biopsy blood tests to identify PIK3CA mutations in patients, who were then assigned to receive either the inavolisib-based regimen or a combination of palbociclib, fulvestrant, and a placebo.
Inavolisib functions by inhibiting the PIK3CA protein's activity, and the combination was generally well-tolerated, with few patients experiencing side effects severe enough to discontinue treatment.
Professor Nick Turner, from the Institute of Cancer Research, London, and Royal Marsden NHS Foundation Trust, led the UK arm of the trial. He stated, "The key findings from this study showed that the inavolisib-based therapy not only helped patients live longer but it more than doubled the time before their cancer progressed or worsened. It also gave them more time before needing subsequent chemotherapy which we know is something that patients really fear and want to delay for as long as possible."