limnetrelvir

**Limnetrelvir (ABBV-903)** is an investigational small molecule antiviral agent developed as a 3C-like protease (MPro or 3CLpro) inhibitor targeting SARS-CoV-2. It covalently binds to the active site of the viral main protease, preventing cleavage of polyprotein precursors essential for viral replication. Unlike nirmatrelvir (PF-07321332), which requires ritonavir boosting, limnetrelvir is designed for improved pharmacokinetics and oral bioavailability as a standalone agent. It is under preclinical or early development for COVID-19 treatment by AbbVie, with no approved indications or clinical trial data publicly available as of current records.[11][14][20]