Leritrelvir inhibited CVB4 replication in vitro (EC50 12.64 nM) and prevented mortality, alleviated symptoms, and attenuated tissue damage in CVB4-infected mice at 12 mg/kg/day.
Leritrelvir shows potent in vitro and in vivo efficacy against coxsackievirus B4, highlighting its potential for repurposing to treat enterovirus infections.
Enteroviruses (EVs) pose major threats to human health, among which coxsackievirus B4 (CVB4) is particularly notable for its high lethality, increasing prevalence, and the absence of approved targeted therapeutics. Leritrelvir, an approved coronavirus disease 2019 (COVID-19) drug targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3C-like protease (3CL pro ), was investigated for repurposing due to structural and functional homology between the EV 3C protease (3C pro ) and SARS-CoV-2 3CL pro . Molecular docking analyses demonstrated that leritrelvir binds to the CVB4 3C pro active site in a manner similar to that observed for SARS-CoV-2 3CL pro . In vitro experiments showed that leritrelvir inhibited CVB4 replication in HeLa cells, with a half-maximal effective concentration (EC 50 ) of 12.64 nM. The half-maximal cytotoxic concentration (CC 50 ) of leritrelvir in HeLa cells was 572.7 μM, yielding a selectivity index (SI=CC 50 /EC 50 ) of 4.53×10 4 . Among 3-day-old ICR mice infected with CVB4, leritrelvir suppressed viral replication in a dose-dependent manner. Administration of leritrelvir (12 mg/kg/day) prevented mortality, alleviated clinical symptoms and weight loss, and attenuated histopathological lesions in virus-targeted organs (e.g., brain, lungs, myocardium, and small intestine). Additionally, leritrelvir effectively suppressed CVB4-induced elevation of interleukin-6. Leritrelvir exhibited superior anti-CVB4 efficacy both in vitro and in vivo compared with the reference drug fluoxetine. Potent activity was observed against CVB4 clinical isolates and 3C pro mutants, confirming broad-spectrum efficacy against CVB4 variants. In vitro and in silico analyses revealed that leritrelvir exerted robust antiviral effects against EVA71, CVA16, and human rhinovirus 2. These findings support the repurposing potential of leritrelvir against CVB4 and common EVs. • Leritrelvir binds CVB4 3C pro and inhibits replication in vitro • Leritrelvir prevents mortality, symptoms, and tissue damage in CVB4-infected mice • Leritrelvir suppresses CVB4-induced serum IL-6 elevation • Leritrelvir exhibits broad activity against CVB4 clinical isolates and 3C pro mutants • Leritrelvir shows effects against common enteroviruses in silico and in vitro
Liu et al. (2026) studied Coxsackievirus B4 and common enterovirus infections. Leritrelvir vs. Fluoxetine / untreated was evaluated on Viral replication, mortality, clinical symptoms, and histopathological lesions. Leritrelvir inhibited CVB4 replication in vitro (EC50 12.64 nM) and prevented mortality, alleviated symptoms, and attenuated tissue damage in CVB4-infected mice at 12 mg/kg/day.