Poop pills may help boost cancer immunotherapy

Two small trials published in Nature Medicine reported that oral fecal microbiota transplant (FMT) pills were associated with fewer immunotherapy side effects in advanced kidney cancer and higher response rates in advanced lung cancer and melanoma.

Two small Canadian trials published in Nature Medicine tested oral fecal microbiota transplantation (FMT) pills given alongside cancer immunotherapy. One trial involved people with metastatic renal cell (kidney) carcinoma and the other involved people with advanced lung cancer or melanoma. Both trials used pills developed by researchers at the Lawson Research Institute and included international collaborators. The studies are early and modest in size, so researchers describe the findings as preliminary. Key takeaways: - A Phase I trial of 20 people with metastatic renal cell carcinoma reported fewer immunotherapy-related side effects and about a 50% treatment response, though the trial was not primarily designed to assess effectiveness. - A Phase II trial in people with advanced lung cancer or melanoma reported response rates of roughly 75%–80%, compared with typical response ranges cited for immunotherapy alone of about 39%–45%. - Both studies used oral FMT pills and the authors and institutions involved say larger, more extensive trials are needed to confirm these findings. Summary: The studies suggest oral FMT pills may influence how some patients respond to cancer immunotherapy and may affect treatment side effects, but the evidence is limited by small sample sizes. Researchers and institutions involved report these results as preliminary and say larger trials are underway to test FMT with immunotherapy further.