A new oral SARS-CoV-2 protease inhibitor for treating COVID-19

Nirmatrelvir/ritonavir (Paxlovid), a SARS-CoV-2 protease inhibitor, is first-line therapy for high-risk, non-hospitalised patients with COVID-19 (JAMA 2023; 330:1519).

Now, investigators in China report the results of a placebo-controlled trial of another SARS-CoV-2 protease inhibitor, simnotrelvir/ritonavir, in adults with mild-to-moderate COVID-19 during the Omicron era.

Simnotrelvir/ritonavir has been conditionally approved in China for treatment of mild-to-moderate COVID-19. This study adds to the evidence that early initiation of antiviral therapy yields more-rapid resolution of COVID-19 symptoms.

As is the case for influenza therapeutics, symptom resolution is likely to be the key endpoint of future COVID-19 antiviral trials because progression to severe disease is uncommon in vaccinated individuals unless they are immunocompromised, have comorbidities, or are of advanced age.