Bench-to-Bedside Development of IMNN-001: A Non-Viral IL-12 Gene Therapy for Advanced Ovarian Cancer

Interleukin-12 (IL-12) is a potent immunostimulatory cytokine with well-established antitumor activity, but systemic recombinant IL-12 administration has been constrained by inflammatory toxicity, high circulating cytokine peaks, and insufficient tumor-local exposure. IMNN-001 is a non-viral IL-12 gene therapy candidate based on the TheraPlas® platform comprising an IL-12 expression plasmid formulated with synthetic polyethylene glycol-polyethyleneimine-cholesterol (PEG-PEI-cholesterol; PPC). Administered intraperitoneally, IMNN-001 is designed to enable regional transfection, localized IL-12 production for several days after a single injection, and repeatable pharmacodynamics activity within the peritoneal disease compartment. This review summarizes the rationale, formulation attributes, gene-transfer properties, pharmacodynamic durability, mechanism of action, biodistribution, toxicology, manufacturing controls, and clinical development of IMNN-001. Across preclinical and clinical studies, intraperitoneal delivery of IMNN-001 has produced preferential cytokine induction in ascites, with substantially higher IL-12 and interferon gamma (IFN-γ) levels in ascites than in blood. These effects were accompanied by immune remodeling including a favorable shift in the balance between immunostimulatory and immunosuppressive cells. In recurrent disease, activity varied by regimen and disease setting, whereas a randomized phase I/II study in newly diagnosed advanced ovarian cancer showed numerical differences in progression-free and overall survival that require confirmation in an adequately powered trial, currently in progress. Reported toxicities were predominantly local or attributable to combination therapy, although abdominal pain and catheter-related complications have been observed. An ongoing Phase III trial is evaluating whether adding IMNN-001 to standard chemotherapy improves clinical outcome. Objectives. The objective of this review is to place IMNN-001 within the broader challenge of developing safer and more effective IL-12-based cancer immunotherapies by examining how regional, non-viral gene delivery may overcome the limitations of systemic recombinant IL-12, including short circulating half-life, high systemic cytokine peaks, and dose-limiting inflammatory toxicity. Specifically, the review summarizes the IMNN-001 product rationale, formulation design, gene-transfer and transfection properties, pharmacodynamic durability, mechanism of action, immune remodeling, biodistribution, toxicology, manufacturing and stability attributes, and clinical development experience in ovarian cancer. By integrating preclinical, translational, CMC, and clinical findings, the article aims to define the scientific and clinical basis for IMNN-001 as a compartmentally targeted, durable, and repeatable IL-12 gene therapy strategy, while also positioning it within the broader landscape of emerging IL-12 delivery approaches and future therapeutic opportunities. This is a development-focused review of IMNN-001 technology and product.