Reprogramming Immunosuppressive Niches and the Cancer Immunity Cycle in Pancreatic Cancer with Neoantigen mRNA Plus Immune Adjuvant Nanocarrier Strategies

Pancreatic ductal adenocarcinoma (PDAC) remains among the most lethal malignancies, driven by an immune-excluded, desmoplastic tumor microenvironment (TME), a low neoantigen burden, and resistance to immune checkpoint blockade. Recent progress in immunotherapy has emerged from two complementary fronts─personalized mRNA vaccination and nanomedicine-based immune reprogramming. Clinically, the autogene cevumeran (BNT122) mRNA-lipoplex vaccine demonstrated that individualized neoantigen delivery can elicit durable, tissue-resident CD8⁺ T cells and prolong recurrence-free survival in resected PDAC, marking a breakthrough in restoring adaptive immunity to an otherwise "cold" tumor. Preclinically, multifunctional nanocarriers have expanded this potential to advanced disease: lipid nanoparticles (LNPs) codelivering mutant KRAS G12D mRNA and the STING agonist, cGAMP, reprogram tolerogenic hepatic antigen-presenting cells into immune activators, inducing type I interferon signaling and the ability to eradicate liver metastases in murine PDAC models. This approach overcomes the immune protective niche that promotes metastatic cancer growth in the liver. Complementary silicasome platforms (lipid bilayer coated mesoporous silica nanoparticles) encapsulating irinotecan to induce immunogenic cell death (ICD) synergize with spleen-targeting LNPs carrying KRAS mRNA and TLR7/8 agonists, thereby bridging local antigen release with systemic T-cell priming. Together, these studies establish a translational framework wherein nanoparticle-based immunotherapy can both enhance and extend the benefits of mRNA vaccines from localized to metastatic PDAC. By integrating ICD induction, neoantigen targeting, and immune niche reprogramming, these modular nanomedicine platforms offer a realistic path toward scalable, durable, and systemically effective PDAC immunotherapy.