Programmable Circular Multispecific Aptamer-Drug Engager to Broadly Boost Antitumor Immunity

Safely and effectively harnessing innate immunity to boost cancer immunotherapy is promising yet challenging. Hence, we have developed a series of programmable aptamer-based multispecific engagers by encoding various artificial aptamer-drug codons with DNA-templated polymerization, aiming to broadly boost innate and adaptive immunity for antitumor therapy. All circular single-stranded multivalent aptamer-drug conjugates (os-mvApDCs) had a dendritic structure, precise size, and excellent stability, enabling prolonged blood circulation, targeted tumor accumulation, and rapid multireceptor-mediated endocytosis. A trispecific engager (^Sl/Pd/Mjos-mvApDCs^SMT), targeting PD-1 on CD8⁺ T cells and PD-L1/c-Met on tumor cells, recruited large amounts of immune cells into the tumor and released cytotoxic MMAE and immunomodulators, inducing severe cell death and broad activation of innate immunity. When combined with the αPD-1 blockade, there was a significant increase in the number of CD8⁺ T cells (10-fold increase versus untreated control) engaged and expanded in the tumor, exhibiting potent function (IFN-γ⁺/GzmB⁺) and low exhaustion (PD-1⁺TIM-3⁺). The orchestrated innate and adaptive immunity effectively eliminated immunosuppressive MDSCs, Tregs, and M2-like macrophages in tumors and promoted the maturation of dendritic cells (DCs) in the draining lymph nodes, resulting in robust and durable systemic antitumor efficacy, with 7 out of 8 mice surviving over 60 days. Our programmable DNA-templated printing technology enables the rational design of multispecific therapeutics with modular composition and function but minimal production issues, providing a versatile tool for the development of multifunctional personalized medicine.