A new triple therapy regimen has demonstrated significant success in slowing the progression of advanced breast cancer, extending patient survival, and delaying the need for further chemotherapy, according to research presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
The study, funded by Roche and published in the New England Journal of Medicine, highlights the potential of combining targeted drugs with hormone therapy to improve outcomes for patients with a specific form of the disease. The treatment involves a combination of two targeted drugs, inavolisib and palbociclib, alongside the hormone therapy fulvestrant. The clinical trial found that patients receiving this triple therapy experienced an average overall survival improvement of seven months compared to those in the control group, who were administered only palbociclib and fulvestrant.
Furthermore, disease progression was delayed by an average of 17.2 months for patients on the new regimen, compared to 7.3 months for those on standard therapy. In addition to slowing disease progression, the trial showed that patients receiving the inavolisib-based treatment were able to postpone the need for subsequent chemotherapy by almost two years longer than those in the control group.
Researchers emphasized that delaying chemotherapy can significantly improve the quality of life for patients, as chemotherapy often brings severe side effects and emotional strain. The international phase 3 trial, known as INAVO120, enrolled 325 patients from 28 countries, including the United States, United Kingdom, Australia, Singapore, Brazil, France, and Germany.
The trial specifically targeted patients with PIK3CA-mutated hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer, a subtype that represents about 70 percent of all breast cancer cases. PIK3CA mutations, present in approximately 35 to 40 percent of HR+ breast cancers, are associated with tumor growth, disease progression, and resistance to conventional treatments.
Dr. Jane Lowe Meisel, Co-Director of Breast Medical Oncology at Winship Cancer Institute of Emory University and an ASCO expert, described the findings as a major advancement for patients with this challenging subtype of breast cancer. She noted that the targeted approach offers new hope for individuals with untreated PIK3CA-mutated metastatic disease.
Data from the study also indicated a significant tumor shrinkage rate, with 62.7 percent of patients in the triple therapy group showing tumor reduction, compared to 28 percent in the control group. Dr. Simon Vincent, Director of Research at Breast Cancer Now, called the findings a “significant breakthrough” in the ongoing effort to develop more effective treatments for breast cancer.
Dr. Nisharnthi Duggan, Research Information Manager at Cancer Research UK, highlighted the potential quality-of-life benefits for patients, stating that delaying disease progression and chemotherapy not only improves survival but also allows patients more time with their loved ones. She emphasized the importance of continued research to develop kinder treatment options for cancer patients.
The trial utilized circulating tumor DNA (ctDNA) liquid biopsy blood tests to determine whether patients carried the PIK3CA mutation. Participants were then assigned either the inavolisib-based regimen or a combination of palbociclib, fulvestrant, and a placebo. The inavolisib drug works by inhibiting the activity of the PIK3CA protein, which plays a role in cancer cell growth and survival. The combination therapy was generally well tolerated, with only a small number of patients discontinuing due to side effects.
Professor Nick Turner, who led the UK arm of the trial, underscored the importance of the findings, noting that the inavolisib-based therapy not only extended survival but also significantly delayed the worsening of the disease and the need for chemotherapy. He emphasized that delaying chemotherapy is particularly valuable to patients seeking to maintain their quality of life for as long as possible. – By MENA Newswire News Desk.
