Human bronchopulmonary disposition and plasma pharmacokinetics of oral bemnifosbuvir (AT-527), an experimental guanosine nucleotide prodrug for COVID-19.

Background: Bemnifosbuvir (AT-527) is a novel oral guanosine nucleotide antiviral drug for the treatment of persons with COVID-19. Direct assessment of drug disposition in the lungs, via bronchoalveolar lavage, is necessary to ensure antiviral drug levels at the primary site of SARS-CoV-2 infection are achieved.

Objectives: This Phase 1 study in healthy subjects aimed to assess the bronchopulmonary pharmacokinetics, safety and tolerability of repeated doses of bemnifosbuvir.

First-in-human trial evaluating safety and pharmacokinetics of AT-752, a novel nucleotide prodrug with pan-serotype activity against dengue virus.

AT-752 is a novel guanosine nucleotide prodrug inhibitor of the dengue virus (DENV) polymerase with sub-micromolar, pan-serotype antiviral activity. This phase 1, double-blind, placebo-controlled, first-in-human study evaluated the safety, tolerability, and pharmacokinetics of ascending single and multiple oral doses of AT-752 in healthy subjects. AT-752 was well tolerated when administered as a single dose up to 1,500 mg or when administered as multiple doses up to 750 mg three times daily (TID).

Phase II study of bemnifosbuvir in high-risk participants in a hospital setting with moderate COVID-19.

Background: Bemnifosbuvir, a novel, oral, nonmutagenic, nonteratogenic nucleotide analogue inhibits SARS-CoV-2 replication .

Materials & Methods: Adults in hospital settings with moderate COVID-19 were randomized 1:1 bemnifosbuvir/placebo. Study amended to two parts after interim analysis; part B enrollment limited owing to evolving standard of care.

Oral bemnifosbuvir (AT-527) vs placebo in patients with mild-to-moderate COVID-19 in an outpatient setting (MORNINGSKY).

This phase III study assessed the efficacy/safety/antiviral activity/pharmacokinetics of bemnifosbuvir, a novel, oral nucleotide analog to treat COVID-19. 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.