Atea Pharma Updates on Global Phase 3 SUNRISE-3 Trial for COVID-19 Treatment

BOSTON, Sept. 13, 2024 – Atea Pharmaceuticals, Inc. (Nasdaq: AVIR) ("Atea"), a company in the clinical stage of developing oral antiviral treatments for serious viral diseases, has disclosed the results of the global Phase 3 SUNRISE-3 trial. This trial examined the efficacy of bemnifosbuvir, an oral nucleotide polymerase inhibitor, against a placebo for treating COVID-19. Unfortunately, the trial did not achieve its primary goal of showing a statistically significant reduction in all-cause hospitalization or death by Day 29 among the 2,221 high-risk patients with mild to moderate COVID-19.

In the SUNRISE-3 trial, bemnifosbuvir was found to be generally safe and well tolerated. Dr. Jean-Pierre Sommadossi, CEO and Founder of Atea Pharmaceuticals, expressed disappointment over the trial's outcome. He pointed out that COVID-19 variants are continuously evolving, leading to milder forms of the disease and subsequently fewer hospitalizations and deaths. This trend made it challenging for a direct-acting antiviral to significantly influence the disease's progression. He also commended his team for their diligent execution of the trial amidst the ever-changing pandemic scenario.

Dr. Janet Hammond, Chief Development Officer of Atea Pharmaceuticals, also shared her disappointment. She thanked the study participants and investigators for their contributions. Despite the trial's unsatisfactory outcome and the decision to halt the regulatory pathway forward, Dr. Hammond believes the findings contribute to the broader understanding of COVID-19's evolution.

Atea Pharmaceuticals will now focus on developing a combination treatment of bemnifosbuvir and ruzasvir for hepatitis C. The company plans to release additional Phase 2 trial results in the fourth quarter of 2024.

The Phase 3 SUNRISE-3 trial was global, multicenter, randomized, double-blind, and placebo-controlled. It specifically included high-risk outpatients with mild or moderate COVID-19, who were randomized in a 1:1 ratio to receive either bemnifosbuvir 550 mg twice daily or a placebo for five days, in addition to their local standard of care. The main goal was to measure all-cause hospitalization or death by Day 29 in the monotherapy cohort. Secondary endpoints evaluated patient outcomes up to Day 60 post-treatment.

Bemnifosbuvir is an investigational, orally administered guanosine nucleotide analog polymerase inhibitor, designed to inhibit enzymes critical to viral replication. This novel drug combines a unique nucleotide scaffold with double prodrugs to maximize the formation of the active metabolite, potentially making it highly effective in preventing the replication and transcription of single-stranded RNA viruses without harming host cells.

Currently, bemnifosbuvir is in Phase 2 development in combination with ruzasvir, an oral NS5A inhibitor, for treating hepatitis C virus (HCV) infection. It has a low risk of drug-drug interactions and is generally safe and well-tolerated, with a distinct mechanism of action and a high barrier to resistance.

Atea Pharmaceuticals is dedicated to discovering, developing, and commercializing oral antiviral therapies to meet the unmet medical needs of patients with severe viral infections. Utilizing deep expertise in antiviral drug development, nucleos(t)ide chemistry, biology, biochemistry, and virology, Atea has developed a proprietary nucleos(t)ide prodrug platform. This platform aims to create new treatments for single-stranded ribonucleic acid (ssRNA) viruses, a significant cause of severe viral diseases. Atea intends to expand its antiviral product pipeline by combining its nucleos(t)ide platform with other antiviral classes.