Emerging Precision Therapeutic Strategies in Pancreatic Ductal Adenocarcinoma: KRAS Targeting, DDR Vulnerabilities, Immune Redirection, and Tumor Microenvironment Remodeling.

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies because of aggressive tumor biology, pervasive therapeutic resistance, rapid adaptive reprogramming, and a profoundly immunosuppressive tumor microenvironment. This review summarizes recent advances in KRAS-targeted therapies, DNA damage response (DDR)-directed strategies, immune-redirection platforms, and tumor microenvironment modulation. Methods: We conducted a narrative review of peer-reviewed publications, clinical trial reports, trial registries, and selected conference data addressing emerging therapeutic strategies for PDAC. Results: KRAS-targeted therapies, including KRAS G12D-selective and multi-selective RAS(ON) inhibitors, have demonstrated substantial preclinical and emerging clinical activity while revealing diverse mechanisms of adaptive resistance. DDR-directed approaches are expanding beyond BRCA-mutated disease toward functional homologous recombination deficiency, replication stress, and synthetic lethality. In parallel, bispecific antibodies, T-cell engagers, and CAR-T-cell therapies have generated preliminary evidence of antitumor activity, although stromal exclusion, antigen heterogeneity, and immune suppression remain major barriers. These advances indicate that therapeutic resistance in PDAC is a dynamic process involving interconnected oncogenic, genomic, stromal, metabolic, and immune mechanisms. Conclusions: Future progress will require biologically informed treatment frameworks integrating complementary therapeutic modalities according to baseline tumor biology and treatment-induced adaptive states, supported by longitudinal biomarkers and rational clinical trial design.