The Enzyme Commission refers to this family as SARS coronavirus main proteinase (Mpro; EC 3.4.22.69).
A number of protease inhibitors are being developed targeting 3CLpro and homologous 3Cpro, including CLpro-1, GC376, rupintrivir, lufotrelvir, PF-07321332, and AG7404.
[15] After clinical trials, in December 2021, the oral medication nirmatrelvir (formerly PF-07321332) became commercially available under emergency use authorizations (EUA), as part of the nirmatrelvir/ritonavir combination therapy (brand name Paxlovid).
[19][20] In 2022, an ultralarge virtual screening campaign of 235 million molecules was able to identify a novel broad-spectrum inhibitor targeting the main protease of several coronaviruses.
They are divided into subfamilies by sequence similarity, corresponding to the family of viruses they are found in:[22] Additional members are known from Potyviridae and non-Coronaviridae Nidovirales.