Immune-stimulating antibody drug conjugate (ISAC) can not only effectively solve the defects of stimulator of interferon genes (STING) agonists by coupling antibodies with STING agonists through the targeting of antibodies, but also play a synergistic role with antibodies to further improve the efficacy of STING agonists. This review first provides a concise overview of the current research landscape of ISACs and STING agonists, systematically elaborates on evolving trends in STING agonist development, and subsequently summarizes the mechanistic advances in STING ISAC research. Special emphasis is placed on representative STING ISAC candidates in preclinical/clinical development. Finally, the future directions of STING ISACs are critically discussed with perspectives and recommendations, aiming to provide theoretical insights and practical guidance for future investigations.

Recent progress in targeted metabolic therapy of cancer has been limited by the considerable toxicity associated with such drugs. To address this challenge, we developed a smart theranostic prodrug system that combines a fluorophore and an anticancer drug, specifically 6-diazo-5-oxo-l-norleucine (DON), using a thioketal linkage (TK). This system enables imaging, chemotherapy, photodynamic therapy, and on-demand drug release upon radiation exposure. The optimized prodrug, DON-TK-BM3, incorporating cyanine dyes as the fluorophore, displayed potent reactive oxygen species release and efficient tumor cell killing. Unlike the parent drug DON, DON-TK-BM3 exhibited no toxicity toward normal cells. Moreover, DON-TK-BM3 demonstrated high tumor accumulation and reduced side effects, including gastrointestinal toxicity, in mice. This study provides a practical strategy for designing prodrugs of metabolic inhibitors with significant toxicity stemming from their lack of tissue selectivity.

EIDD-2801 is an orally bioavailable prodrug, which will be applied for emergency use authorization from the U.S. Food and Drug Administration for the treatment of COVID-19. To investigate the optimal parameters, EIDD-2801 was optimized