Spatially tuned localization of interleukins and OX40 agonists enhances synergistic anti-tumor immunity.

While advances in immunotherapy have revolutionized care for cancer patients, most approaches still fail to mount a robust anti-cancer effect. To address this challenge, the field has turned to combination immunotherapies, but systemic administration of potent combination therapies has resulted in severe immune-related adverse effects. Here, we use an injectable polymer-nanoparticle (PNP) hydrogel to rationally localize immunotherapeutic cytokines (IL-12 and IL-2) intratumorally and antibodies (OX40a) peritumorally. We hypothesize that selectively altering the biodistribution of these cargo enables tolerable and synergistic anti-cancer combinations. Using in vivo imaging, we demonstrate that administration sites are critical for redistributing cargo to either the tumor or tumor-draining lymph node (tdLN). Further, we demonstrate that this approach synergistically improved treatment efficacy in the B16F10 and MC38 tumor models and alters cellular phenotypes, resulting in significant tumor clearance in both single and double tumor models.