MXB-9

**MXB-9** is an investigational antiviral **peptoid** developed by **Maxwell Biosciences**. It is a sequence-specific oligo-N-substituted glycine peptidomimetic designed to mimic the human cathelicidin **LL-37** while improving stability through resistance to proteolytic degradation. Preclinical studies have reported activity against enveloped viruses including **SARS-CoV-2**, **herpes simplex virus 1**, and murine hepatitis virus model strains. The proposed mechanism is **direct disruption of the viral envelope membrane** rather than inhibition of a single viral protein target, making it a host-defense-peptide-inspired, membrane-active antiviral candidate. Reported development has remained **preclinical**, with published work emphasizing infectious disease applications such as COVID-19 and herpes labialis.