Bemnifosbuvir SUNRISE-3 trial in High-Risk Outpatients with COVID-19: Patient enrollment continues in the global, randomized, double-blind, placebo-controlled, registrational Phase 3 SUNRISE-3 trial evaluating bemnifosbuvir, a nucleotide polymerase inhibitor, administered concurrently with locally available standard of care. The study is designed to enroll at least 1,500 high-risk outpatients with mild or moderate COVID-19 at clinical trial sites worldwide, including in the U.S., Europe, and Japan. Patients are being randomized 1:1 to receive locally available standard of care and either bemnifosbuvir 550 mg twice-daily (BID) or placebo BID for five days. The primary endpoint of the study is all-cause hospitalization or death through Day 29 in the supportive care population comprised of at least 1,300 patients.
Presentation of Bemnifosbuvir Data Showing Reduced Hospitalizations for COVID-19 Patients at 2023 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2023): In April, Atea presented the full results from the MORNINGSKY trial, which evaluated bemnifosbuvir for the treatment of mild to moderate COVID-19. As previously announced, these results showed that non-hospitalized adult and adolescent patients who received bemnifosbuvir experienced a 71% relative reduction in risk of hospitalization, regardless of vaccination status (secondary endpoint). In an exploratory analysis, an 82% reduction in risk of hospitalization was seen in a subset of patients greater than 40 years of age. Based on these data, the global Phase 3 SUNRISE-3 registrational trial was initiated.
Favorable Drug Interaction Profile of Bemnifosbuvir Presented at 36th International Conference on Antiviral Research (ICAR 2023): In March, Atea presented Phase 1, in vitro and preclinical data that demonstrated key profile attributes of bemnifosbuvir. The data presented included results from a Phase 1 human absorption, distribution, metabolism, and excretion (ADME) study for bemnifosbuvir demonstrating a favorable ADME profile supportive of the dosing regimen being evaluated in SUNRISE-3. In vitro metabolism and transporter interaction studies showed bemnifosbuvir has a low risk for interactions with medicines commonly taken by COVID-19 high risk patients for other conditions. In vitro studies also demonstrated advantages of bemnifosbuvir’s mechanism of action, which targets conserved regions of the virus that causes COVID-19. These potential advantages include a high barrier to resistance and maintenance of antiviral activity in the presence of COVID-19 variants.
Favorable Profile of Bemnifosbuvir Related to Low Risk for Drug-Drug Interactions Presented at Conference on Retroviruses and Opportunistic Infections (CROI 2023): In February, Atea presented data from three Phase 1 studies that showed the favorable drug-drug interaction profile of bemnifosbuvir. The results of these studies, including a study with midazolam, indicate that no dosage adjustment of CYP3A substrates or of drugs that are sensitive substrates of efflux and hepatic uptake transporters is likely to be needed when co-administrated with bemnifosbuvir. CYP3A is an enzyme that metabolizes many classes of medicines and medicinal supplements, and efflux/hepatic uptake transporters regulate cellular trafficking of many medicines that are commonly prescribed to COVID-19 high risk patients.
Bemnifosbuvir Retains Antiviral Activity Against Omicron Subvariant XBB In Vitro: AT-511, the free base of bemnifosbuvir, has been shown to be a potent inhibitor of SARS-CoV-2 in vitro. New results demonstrated that AT-511 retained potent antiviral activity against the SARS-CoV-2 Omicron subvariant XBB. AT-511 has previously demonstrated in vitro potent antiviral activity against other variants of concern and/or of interest, including Alpha, Beta, Gamma, Epsilon, Delta and Omicron subvariants BA.1, BA.2, BA.4, and BA.5.
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