Benzinga | Jun 30, 2021 07:04AM EDT

Atea Pharmaceuticals Announces Interim Results From Phase 2 Study Of AT-527 Showing 'Rapid and Sustained Antiviral Activity Against SARS-CoV-2 in Patients with COVID-19 in the Hospitalized Setting'

Phase 2 Interim Virology Results Indicate Rapid and Sustained Antiviral Activity Against SARS-CoV-2 in Patients with COVID-19 in the Hospitalized Setting

AT-527 is Being Studied in Multiple Clinical Studies, Including Global Phase 2 MOONSONG and Phase 3 MORNINGSKY Trials, with Results Expected During 2H 2021

BOSTON, Mass., June 30, 2021 (GLOBE NEWSWIRE) -- Atea Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company engaged in the discovery and development of oral therapeutics for severe viral infections, today announced positive interim results from the global Phase 2 study evaluating AT-527 in hospitalized patients with mild-to-moderate COVID-19. Roche and Atea are jointly developing AT-527, an oral direct-acting antiviral (DAA) agent derived from Atea's purine nucleotide prodrug platform.

The interim analysis of the Phase 2 study included data from 70 hospitalized, high-risk patients with COVID-19 of which data from 62 patients were evaluable for virology analysis. Interim virology results indicated that AT-527 rapidly reduced viral load levels. At Day 2, patients receiving AT-527 experienced a 0.7 log10 (80%) greater mean reduction from baseline viral load as compared to placebo. A sustained difference in viral load reduction was maintained through Day 8.

AT-527's SARS-CoV-2 potent antiviral activity was also observed in patients with higher baseline viral loads above the median of 5.26 log10 as compared to placebo. When evaluating a strict RT-qPCR threshold of 500 copies/mL with no detectable ribonucleic acid (RNA) virus (target not detected, TND), the AT-527 arm achieved SARS-CoV-2 clearance as early as Day 2 (in 6% of patients), Day 8 (in 7% of patients) Day 10 (in 33% of patients), and Day 12 (in 31% of patients) compared to 0% of patients in the placebo arm at the same timepoints. By Day 14 (last viral sampling study day) approximately 47% of patients in the AT-527 arm and 22% in the placebo arm had no detectable RNA virus (TND). Nasopharyngeal swabs were measured in a reverse transcription polymerase chain reaction test (RT-qPCR) for the quantitative detection of nucleic acid from SARS-CoV-2.

Consistent with previous studies, AT-527 was generally safe and well tolerated. In this hospitalized study, there were no drug-related serious adverse events. Non-serious adverse events were equally distributed across treatment arms. Most were mild-to-moderate in severity and assessed as not related to the study drug. No safety concerns or newly determined risks were identified.

"We are very pleased with the potent antiviral activity of AT-527 demonstrated by the rapid inhibition of SARS-CoV-2 replication. Such potent activity may lead to faster recovery time for patients with COVID-19 while minimizing the transmission of infection," said Jean-Pierre Sommadossi, PhD, Chief Executive Officer and Founder of Atea Pharmaceuticals. "As COVID-19 continues to evolve worldwide, we need a multi-pronged approach to control this disease. AT-527, an oral, potent, target-specific DAA, may offer a convenient treatment to prevent disease progression and allow people to resume daily life more quickly, especially in areas where vaccines and antibody therapies are not readily available."

"The safety and tolerability profile for AT-527 continues to provide us with confidence that it has the potential to be used in hospitalized and outpatient settings for treatment and prophylaxis, which should significantly alleviate the burden on healthcare systems," said Janet Hammond, MD, PhD, Chief Development Officer of Atea. "As we continue to advance our clinical development program, we look forward to sharing further results and analyses, including reporting results from the Phase 2 MOONSONG virology study in the outpatient setting. This multi-cohort data from MOONSONG, which we expect in the third quarter, will further inform AT-527 dosing regimens in various clinical settings."

Final data from the full Phase 2 program will be submitted to an upcoming medical congress or a peer-reviewed publication.