Comprehensive preclinical evaluation of second-generation miRNA-regulated Coxsackievirus B3-BHP: Potent antitumor efficacy and safety.

Oncolytic virotherapy employing Coxsackievirus B3 has emerged as a promising and innovative strategy for cancer treatment. However, wild-type Coxsackievirus B3 is associated with significant organ toxicities, such as viral hepatitis, myocarditis, and pancreatitis, which have presented major obstacles to its clinical application. In this study, we engineered a second-generation recombinant Coxsackievirus B3 (CVB3-BHP) by incorporating target sequences for the pancreas-specific miR-217 and the miR-34a, which is predominantly expressed in normal tissues, to further enhance its safety profile. Preclinical evaluation demonstrated that CVB3-BHP exhibited potent and dose-dependent antitumor efficacy in murine tumor models, with complete tumor regression or marked shrinkage observed in the high-dose group. Biodistribution analysis showed that CVB3-BHP transiently accumulated in the spleen and lacrimal gland but was rapidly cleared from these tissues over time, with limited excretion in urine and feces. Toxicity assessment indicated that even repeated high-dose administration did not induce overt systemic toxicity or organ damage. Although mild inflammation and acinar atrophy were observed in the lacrimal gland, no clinically significant adverse events were observed. Collectively, these findings indicate that CVB3-BHP combines robust antitumor efficacy with an improved safety profile, supporting its potential as a strong candidate for clinical translation in oncolytic virotherapy.