First clinical study using HCV protease inhibitor danoprevir to treat COVID-19 patients

As coronavirus disease 2019 (COVID-19) outbreak globally, repurposing approved drugs is emerging as important therapeutic options. Danoprevir boosted by ritonavir (Ganovo) is a potent hepatitis C virus (HCV) protease (NS3/4A) inhibitor, which was approved and marketed in China since 2018 to treat chronic hepatitis C patients.

This is an open-label, single arm study evaluating the effects of danoprevir boosted by ritonavir on treatment naïve and experienced COVID-19 patients for the first time. Patients received danoprevir boosted by ritonavir (100 mg/100 mg, twice per day). The primary endpoint was the rate of composite adverse outcomes and efficacy was also evaluated.

The data showed that danoprevir boosted by ritonavir is safe and well tolerated in all patients. No patient had composite adverse outcomes during this study. After initiation of danoprevir/ritonavir treatment, the first negative reverse real-time PCR (RT-PCR) test occurred at a median of 2 days, ranging from 1 to 8 days, and the obvious absorption in CT scans occurred at a median 3 days, ranging from 2 to 4 days. After 4 to 12-day treatment of danoprevir boosted by ritonavir, all enrolled 11 patients were discharged from the hospital.

Our findings suggest that repurposing danoprevir for COVID-19 is a promising therapeutic option.