Chimerix, Inc. in collaboration with the Antiviral Drug Development Initiative at the University of North Carolina at Chapel Hill announced that preclinical data from the Company's CMX521 program will be featured in a late-breaking oral presentation session at the International Conference on Antiviral Research (ICAR) on March 23, 2022 from 12:15 – 1:00 pm PT. Monotherapy prophylactic administration of aerosol CMX521 every eight hours starting eight hours prior to infection reduced average viral titers in lung on day four post-infection by 3.62 log10 (>99.9% reduction) and prevented weight loss/clinical progression versus placebo. Antiviral efficacy was also demonstrated with monotherapy treatment when CMX521 was initiated post-infection.

CMX521 treatment significantly reduced SARS-CoV-2 in the lung (Kruskal-Wallis p<0.0001) and protected mice from clinical symptoms of disease including weight loss and adverse lung pathology (p<0.0001) at day four post-infection relative to placebo. CMX521 is not mutagenic, clastogenic, or associated with mitochondrial toxicity. In addition, oral CMX521 demonstrated a favorable profile in GLP toxicology studies and was well-tolerated up to 2,400 mg in a healthy volunteer Phase 1 study for a different indication.