A phase 2a TACITO trial suggests that Fecal Microbiota Transplantation (FMT) from treatment responders may improve outcomes in metastatic renal cell carcinoma. Patients received standard immunotherapy with pembrolizumab and axitinib, along with either donor FMT or a placebo.
Results showed clear benefits for the donor FMT group. Median progression-free survival was 24 months versus 9 months in the placebo group, and 70% of patients remained progression-free at 12 months compared to 41%. Overall survival also trended higher (41.0 vs. 28.3 months), though confirmation is ongoing. The treatment was well tolerated, with no major side effects linked to FMT.
Patients received three FMT treatments over six months, starting with colonoscopy followed by capsules. Donors were carefully selected from patients with strong prior responses. Lead author Serena Porcari noted that larger studies are needed to confirm findings and address donor supply challenges.