Oral Bemnifosbuvir (AT-527) Vs Placebo in Patients With mild-to-moderate COVID-19 in an Outpatient Setting (MORNINGSKY)
Arantxa Horga, Rebecca Saenz, Gürdal Yılmaz, Jesus Abraham Simón Campos, Keith Pietropaolo, William Stubbings, Neil Collinson, Laura Ishak, Barbara Zrinscak, Bruce Belanger, Catherine Granier, Kai Lin, Aeron C. Hurt, Xiao‐Jian Zhou, Steffen Wildum, Janet Hammond
Abstract
Aim: This phase III study assessed the efficacy/safety/antiviral activity/pharmacokinetics of bemnifosbuvir, a novel, oral nucleotide analog to treat COVID-19. Patients & methods: Outpatient adults/adolescents with mild-to-moderate COVID-19 were randomized 2:1 to bemnifosbuvir/placebo. Time to symptom alleviation/improvement (primary outcome), risk of hospitalization/death, viral load and safety were evaluated. Results: Although the study was discontinued prematurely and did not meet its primary end point, bemnifosbuvir treatment resulted in fewer hospitalizations (71% relative risk reduction), COVID-19-related medically attended hospital visits, and COVID-19-related complications compared with placebo. No reduction in viral load was observed. The proportion of patients with adverse events was similar; no deaths occurred. Conclusion: Bemnifosbuvir showed hospitalization reduction in patients with variable disease progression risk and was well tolerated. Clinical Trial Registration: NCT04889040 (ClinicalTrials.gov).