Efficacy and Safety Assessment of 5-Fluorouracil, Irinotecan and Oxaliplatin-Loaded Implants in Mouse and Pig Models for Pancreatic Cancer Therapy.

Pancreatic ductal adenocarcinoma (PDAC) remains highly resistant to treatment, with mortality rates largely unchanged despite advances in cancer therapies. For ∼80% of borderline, non-resectable, or metastatic cases, chemotherapy is predominantly palliative, underscoring the need for improved drug delivery approaches. This study presents the development, characterization and in vivo evaluation of a novel polymeric implant loaded with 5-fluorouracil, irinotecan, and oxaliplatin (FIRINOX). Scanning electron microscopy of FIRINOX implants showed internal microstructure was preserved upon drug loading, while micro-CT and X-ray imaging revealed valuable insights into the morphology and degradation of implants retrieved from in vivo experiments. In murine PDAC models, dose-escalation identified 4 × FIRINOX implants as the maximum tolerated dose, while 2 × implants achieved significant therapeutic efficacy at lower doses than IV administration, without compromising animal safety. In healthy pigs, 20 × FIRINOX implants were well-tolerated, as confirmed by histopathology and blood analysis. Finally, laser ablation-inductively coupled plasma-mass spectrometry imaging and microbiome analysis confirmed localized drug perfusion within tissues, and minimal off-target effects, including preservation of gut microbiota diversity. These findings support the potential of this implantable platform to improve outcomes in borderline or non-resectable PDAC and enhance tolerability of cytotoxic chemotherapy through localized, controlled delivery, addressing a key gap where current treatment options are limited.