Localized Multi-Component Delivery Platform Generates Local and Systemic Anti-Tumor Immunity

As tumors employ complementary overlapping and/or independent mechanisms to evade immune surveillance, many emerging cancer immunotherapies attempt to target multiple pathways to eradicate malignant cells. Although modulation of independent pathways by simultaneous administration of multiple immune modulators (e.g., checkpoint inhibitors, cytokines, and growth factors) has shown great promise, the clinical impact remains limited due to severe toxicity associated with high systemic levels of many of these drugs. Therefore, novel platforms for efficient delivery of multi-component therapies at lower effective doses would be enabling. Here, a drug delivery platform called immunomodulatory molecule delivery system (iMods), which provides sustained extracellular delivery of a checkpoint inhibitor (anti-PD-L1) and simultaneously, targeted intracellular delivery of a tumor antigen (OVA) along with adjuvant (poly(I:C)), and the indoleamine deoxygenase inhibitor 1-MT is described. In melanoma tumor-bearing mice, combinatorial delivery of these factors with iMods leads to regression of both treated and untreated (contralateral) melanoma tumors and 100% survival. These promising therapeutic outcomes are attributed to significantly enhanced ratios of anti-tumor CD8 T-cell/tumor-protective regulatory T-cell (Treg) in tumors and tumor draining lymph nodes. Overall, the iMods delivery platform described here represents a promising advance in multi-factor cancer immunotherapy.