Atea Pharmaceuticals Announces Presentation of Bemnifosbuvir Preclinical Data at the 38th International Conference on Antiviral Research (ICAR) 2025
Atea Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company engaged in the discovery and development of oral antiviral therapeutics for serious viral diseases, today announced the poster presentation of bemnifosbuvir preclinical data at the 38th International Conference on Antiviral Research (ICAR) 2025 taking place March 17-21, 2025 in Las Vegas, Nevada.
Bemnifosbuvir (BEM), an oral prodrug of a 6-modified guanosine nucleotide analog, is a potent HCV NS5B inhibitor being developed in a fixed dose combination regimen with ruzasvir, a highly potent NS5A inhibitor for the treatment of chronic HCV infection. The activation of BEM is mediated by cellular enzymes including CatA/CES1, HINT1, ADALP1, GUK1, and NDPK to yield the intracellular active triphosphate metabolite AT-9010. In this preclinical study, the metabolism of BEM to its active triphosphate was demonstrated to be cell-line dependent, indicating that cell model selection is critical when evaluating in vitro efficacy of antiviral prodrugs such as BEM.
Based upon a successful engagement with the US Food and Drug Administration (FDA) at the End-of-Phase 2 meeting in January 2025, Atea is initiating a global Phase 3 program and expects patient enrollment to start in April 2025.
In December 2024, Atea announced that its Phase 2 study evaluating the regimen of BEM and ruzasvir for the treatment of HCV, met its primary endpoints. Atea plans to conduct two open label Phase 3 trials, one in the US and Canada and one outside of North America. Each Phase 3 trial is expected to enroll approximately 800 treatment-naïve patients, including those with and without compensated cirrhosis. For patients without cirrhosis, 8 weeks of the regimen of BEM and ruzasvir will be compared to 12 weeks of the regimen of sofosbuvir (SOF) and velpatasvir. For patients with compensated cirrhosis, 12 weeks of the regimen of BEM and ruzasvir will be compared to 12 weeks of the regimen of sofosbuvir and velpatasvir. In the US, it is estimated that more than 90% of people with HCV are non-cirrhotic.
About Bemnifosbuvir and Ruzasvir for Hepatitis C Virus (HCV)
BEM has been shown in in vitro studies to be approximately 10-fold more active than SOF against a panel of laboratory strains and clinical isolates of HCV GT 1–5. In vitro studies have also demonstrated BEM remained fully active against SOF resistance-associated substitutions (S282T), with up to 58-fold more potency than SOF. The PK profile of bemnifosbuvir supports once-daily dosing for the treatment of HCV. BEM has been shown to have a low risk for drug-drug interactions. BEM has been administered to over 2,300 subjects and has been well-tolerated at doses up to 550 mg for durations up to 12 weeks in healthy subjects and patients.
Ruzasvir has demonstrated highly potent and pan-genotypic antiviral activity in preclinical (picomolar range) and clinical studies. Ruzasvir has been administered to over 2,100 subjects at daily doses of up to 180 mg for 12 weeks and has demonstrated a favorable safety profile. The PK profile of ruzasvir supports once-daily dosing.
