Opsonization and timing as key determinants of MBTA immunotherapy efficacy in pancreatic adenocarcinoma and recurrence treatment.

BACKGROUND

Pancreatic adenocarcinoma is a highly aggressive cancer with very limited treatment options. This study aimed to optimize the efficacy of a previously developed tumor immunotherapy for the treatment of this disease and its recurrences.

METHODS

Mouse models of pancreatic and colon adenocarcinoma were established using Panc02 and MC38 cells, respectively. Tumors were treated by intratumoral administration of MBTA, a formulation containing resiquimod, poly(I:C), LTA, anti-CD40 antibody, and mannan-BAM (a phagocytosis-stimulating mannan anchored to the tumor cell membrane via a biocompatible membrane anchor, BAM). Multiple variants of the therapy were tested, differing in composition and timing, including treatment of recurrences.

RESULTS

Intratumoral MBTA immunotherapy administered using an optimized 5 × 2 schedule resulted in an 87.5% survival rate in mice bearing subcutaneous Panc02 tumors. MBTA immunotherapy also effectively treated spontaneous local Panc02 recurrences that developed in a small subset of mice. High efficacy of MBTA was further confirmed in a murine model of colon adenocarcinoma.

CONCLUSION

These findings suggest that MBTA is a promising therapeutic approach for primary and recurrent pancreatic adenocarcinoma, with potential for broader clinical application.