Wide-ranging implications
Overall, Dr. Facciabene’s research has shown that:
- Vancomycin significantly enhances the tumor inhibitory effect of targeted radiation, including abscopal effects.
- The synergistic effects are dependent upon IFN-gamma and CD8+ cells.
- Depletion of some gut microbiome species increases antigen presentation by dendritic cells. This is mediated by SCFAs produced by certain bacterial families.
- There are promising new strategies to improve responses to radiotherapy, including targeting gut microbiota.
A clinical trial (NCT03546829) of vancomycin plus stereotactic body radiation in patients with locally advanced non–small cell lung cancer has been launched to investigate these findings further. Early data analysis has shown a significant impact of vancomycin on several species of gut microbiota, according to Dr. Facciabene.
Revolutionary results from immune-targeted therapy in the recent past have highlighted the important role the immune system can play in fighting cancer. Still, up to one-third of cancer patients fail to respond to overtly immune-targeted therapy.
The ability to inhibit cancer cells from evading immune surveillance by using new adjuvants – including those acting on non-traditional targets like gut microbiota – could herald the next major advances in cancer therapy. During his presentation, Dr. Facciabene gave participants an enticing hint of what could be coming for cancer patients in the years ahead.
Dr. Facciabene reported having no relevant disclosures.
Dr. Lyss was a community-based medical oncologist and clinical researcher for more than 35 years before his recent retirement. His clinical and research interests were focused on breast and lung cancers, as well as expanding clinical trial access to medically underserved populations. He is based in St. Louis. He has no conflicts of interest.