Pharmacotranscriptomics-based discovery and hydrogel-mediated delivery of drug combinations for potentiated cancer immunotherapy.

Combination therapy is a widely used clinical strategy to enhance treatment efficacy against solid tumors. However, the diversity of medicinal drugs and the complexity of in vivo delivery processes present significant challenges for the rational selection and efficient delivery of drug combinations. As a proof of concept, we herein developed an omics-based high-throughput drug screening platform, pharmacotranscriptomic signature enrichment analysis (PSEA), for the prediction of drug combinations of resiquimod (R848) to improve macrophage-mediated cancer immunotherapy. By comparing the critical transcriptional signatures of R848 with chemical perturbation signatures from the LINCS database, PSEA identified mitoxantrone (MIT) as a promising candidate. We then engineered an MIT/R848 co-loaded hydrogel (MIT/R848@Gel) and tested its therapeutic effect in multiple tumor models including the MMTV-PyMT transgenic mouse tumor and VX2 rabbit tumor. Local injection of MIT/R848@Gel not only suppressed the growth of primary tumors but also potently inhibited tumor recurrence and metastasis by eliciting durable and robust systemic antitumor immune responses, resulting in long-term remission in a high percentage of animals. Transcriptional and flow cytometry results indicated that MIT/R848@Gel remarkably reprogrammed immunosuppressive macrophages toward an antitumor phenotype and effectively activated the antitumor effect of cytotoxic T cells. This study establishes a novel framework integrating omics-driven drug discovery with localized combination therapy for enhanced cancer immunotherapy.