First patient dosed in SUNRISE-3 phase III registrational trial of bemnifosbuvir, an investigational oral antiviral for the treatment of COVID-19

The patient was enrolled and dosed at a U.S. clinical trial site. The study is designed to enroll at least 1,500 patients with mild or moderate COVID-19, and the primary endpoint is all-cause hospitalization or death through Day 29 in at least 1,300 patients in the monotherapy arm. Bemnifosbuvir is an investigational orally administered, direct-acting antiviral derived from Atea’s purine nucleotide prodrug platform.

“COVID-19 remains a significant cause of morbidity and mortality, particularly in the elderly and immunocompromised. New oral antivirals, with improved profiles, are urgently needed to help those for whom currently available treatments are either unsuitable or ineffective,” said Robert Murphy, MD, Executive Director of the Havey Institute for Global Health and the John Philip Phair Professor of Infectious Diseases at Northwestern University Feinberg School of Medicine.

Bemnifosbuvir, a nucleotide polymerase inhibitor, targets the SARS-CoV-2 RNA polymerase (nsp12), a highly conserved gene that is unlikely to change as the virus mutates and new variants continue to emerge. This gene is responsible for both replication and transcription of SARS-CoV-2. Bemnifosbuvir has a unique mechanism of action, with dual targets consisting of chain termination (RdRp) and nucleotityltransferase (NiRAN) inhibition, which has the potential to create a high barrier to resistance. In vitro data confirm that bemnifosbuvir is active with similar efficacy against all variants of concern or interest that have been tested, including Omicron subvariants BA.4 and BA.5.