Study design and patients.
obesity, chronic kidney or liver disease, COVID-19 illness, chronic metabolic disease, shortness of breath
OBESITY, CHRONIC LUNG DISEASE, CHRONIC METABOLIC DISEASE, CARDIOVASCULAR DISEASE
MOONSONG was a phase 2, randomized, double-blind, placebo-controlled study to assess the antiviral activity, safety, efficacy, and pharmacokinetics of different dosing regimens of bemnifosbuvir in ambulatory patients with mild or moderate COVID-19. Up to 5 cohorts evaluating selected dose regimens were planned (cohorts A to E). An interim analysis of safety and virology data was conducted in cohort A after 30 treated patients reached day 10.Patients were recruited at 12 centers across Canada, Greece, Ireland, Latvia, Spain, and the United Kingdom. Eligible patients were aged ≥18 years with a positive SARS-CoV-2 test at screening (by RT-PCR or rapid antigen test) and mild or moderate COVID-19 symptoms (as determined by investigator), with onset ≤5 days prior to randomization. Otherwise-healthy patients and those at high risk for poor outcomes were eligible (enrollment of high-risk patients was permitted after a protocol amendment, with high risk being defined as age of >50 years, obesity, cardiovascular disease, chronic lung disease, chronic metabolic disease, chronic kidney or liver disease, or immunocompromised patients). Patients were excluded if they showed clinical signs indicating COVID-19 illness requiring hospitalization (defined as any of the following: shortness of breath at rest, respiratory rate of ≥30 breaths per minute, heart rate of ≥125 beats per minute, peripheral capillary oxygen saturation of ≤93% on room air). Full inclusion and exclusion criteria are provided in File S1.All patients gave written informed consent to participate in the study. The study protocol was approved by an institutional review board or ethics committee. The trial was conducted according to the principles of the Declaration of Helsinki, the International Council for Harmonization Guidelines for Good Clinical Practice, and relevant country-specific laws and regulations. The study is registered at 