By analyzing TGCA data and performing tumor modeling in IL-10R KO mice, Sun et al. showed that concurrent IL-10 and high IL-2 signaling correlated with improved tumor control. Combining intratumoral injections of EGFR+ tumor-targeted Cetuximab-based IL-10 and IL-2 immunocytokines boosted efficacy. Antigen-specific intratumoral CD8+ T cells were reactivated, expanded, less exhausted, and dependent on tumor cell MHC-I expression and intratumoral IL-10R+ DCs. IL-10 signaling in macrophages suppressed high-dose IL-2-induced toxicities. Combination therapy enhanced antitumor responses in ex vivo PDTF models.
Contributed by Paula Hochman
ABSTRACT: Tumor-targeting cytokines have emerged as a promising strategy for cancer immunotherapy, although their mechanisms of action often remain complex. In this study, we develop an approach by combining tumor-targeted IL-10 (CmAb-(IL10)2) with IL-2 (CmAb-IL2) to enhance antitumor immunity while minimizing immune-related adverse events (irAEs). We demonstrate that endogenous IL-10 plays a critical role in IL-2-mediated antitumor effects, and that the combination of CmAb-(IL10)2 and CmAb-IL2 preferentially expands less-exhausted CD8+ T cells within tumors. Mechanistically, we identify that the IL-10/IL-10 receptor (IL-10R) axis in dendritic cells (DCs) is critical for mediating the efficacy of this combination therapy by promoting intratumoral DC function. Furthermore, we show that this combination enhances antitumor immune responses in humanized female mice and ex vivo patient-derived tumor fragments models. Our findings reveal that tumor-targeted IL-10 synergizes with IL-2 to enhance antitumor immunity through the IL-10/IL-10R/DC axis within tumors, while mitigating IL-2-associated irAEs through the IL-10/IL-10R/macrophage axis. This approach offers an IL-10 based strategy to improve the efficacy of immunotherapy while reducing irAEs.
