Emerging evidence shows that microbiome influences the outcome of cancer therapy by modulating the host inflammatory response, suggesting a straight correlation between microbiota-mediated immune reactions and efficacy of immune checkpoint inhibitors, such as pembrolizumab.
Both, Dana-Farber Cancer Institute and MEDSIR conducted two independent clinical trials evaluating the role of immunotherapy on the treatment of patients with metastatic HR+/HER2- breast cancer. These two studies investigated the combination of pembrolizumab, an anti-PDL1, with eribulin a commonly used chemotherapeutic agent for pretreated metastatic breast cancer.
In the randomized clinical trial led by Dr. Sara Tolaney’s group at Dana-Farber Cancer Institute the addition of pembrolizumab to eribulin did not improve efficacy outcomes when compared to eribulin alone. The MEDSIR-sponsored trial, was a single-arm study of the combination that suggested results may be better than historical data reported with either pembrolizumab or eribulin alone. Both trials share the common finding of a lack of correlation between PDL1 expression and response to treatment. This raises the need to identify biomarkers beyond PDL1 expression to select those patients who could benefit from this therapy. Both groups, independently, have evaluated the role of microbiome as potential biomarker of immunotherapy response.
The present collaboration opens the opportunity of merging the data from both patient cohorts, thus leading to more robust evidence on the role of microbiota as a possible biomarker of response to immunotherapy.
The establishment of predictive biological markers is of utmost importance to maximize patient benefits and introduce more effective personalized treatments. Both, Dana-Farber Cancer Institute and MEDSIR hope to move one step forward in personalized medicine, helping clinicians to tailor medical treatments to the individual characteristics of each patient.