Nirmatrelvir Plus Ritonavir: First Approval

Nirmatrelvir plus ritonavir (Paxlovid™; Pfizer) is a co-packaged combination of nirmatrelvir and ritonavir tablets, intended for co-administration and developed for the treatment and post-exposure prophylaxis of coronavirus disease 2019 (COVID-19). Nirmatrelvir is a peptidomimetic inhibitor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease, while ritonavir is a human immunodeficiency virus type 1 (HIV-1) protease inhibitor and CYP3A inhibitor. Nirmatrelvir plus ritonavir received its first conditional authorization in December 2021 in the United Kingdom, for the treatment of COVID-19 in adults who do not require supplemental oxygen and who are at increased risk for progression to severe COVID-19. In January 2022, nirmatrelvir plus ritonavir received authorization in the EU for use in the same indication. Nirmatrelvir plus ritonavir is authorized for emergency use in the USA. This article summarizes the milestones in the development of nirmatrelvir plus ritonavir leading to its first authorizations and approval for the treatment of COVID-19.