Synergistic Effect of Fecal Microbiota Transplantation, γδT Cell Immunotherapy, and Pembrolizumab in Refractory...

Pancreatic cancer (PC) remains one of the most lethal malignancies with limited treatment options, particularly in advanced stages. Emerging immunotherapeutic strategies, such as Gamma Delta (γδ) T cell therapy paired with microbiota management, have demonstrated promise.

We report a case of a 75-year-old male diagnosed with advanced-stage and poorly differentiated PC who demonstrated significant clinical improvement following a novel therapeutic approach combining fecal microbiota transplantation (FMT), γδ T cell therapy, and pembrolizumab. Initial chemotherapy and radiotherapy were discontinued due to adverse effects. Pre-treatment the CA19-9 (1206 U/mL), tumor markers were significantly elevated with CEA, CA15-3 and CA125 all within normal limits. No pathogenic mutations (e.g., BRCA1/2, PALB2) were identified. A comprehensive assessment revealed tumor progression, immunosuppression, and gut microbiota dysbiosis, resulting in FMT and γδ T cell therapy being introduced alongside pembrolizumab.

The combination therapy resulted in the clearance of circulating tumor cells (CTCs), normalization of CA19-9 to 72 U/mL, improved clinical symptoms, and a marked reduction in tumor size, as confirmed by CT. Tolerability was excellent with no serious adverse events occurred.

This case suggests that FMT combined with γδ T cell therapy may be a promising immunotherapeutic strategy for advanced PC. Further studies are needed to validate these findings.