An antiviral treatment under development by Atea Pharmaceuticals is showing promise against COVID-19. Recently announced interim results from a Phase II study showed that the asset achieved antiviral activity in healthy patients and set the stage for the drug’s potential as a preventative treatment for COVID following exposure to the virus.
AT-527 is an oral direct-acting antiviral agent developed from Atea’s nucleotide prodrug platform. The antiviral drug blocks viral RNA polymerase, which is needed for viral replication. The asset is being investigated in multiple trials against COVID-19. It is being studied in hospitalized settings and outpatient settings and for the treatment of long-haul COVID-19.
Last year, Boston-based Atea partnered with Swiss pharma giant Roche on the development of AT-527. The two companies initiated a Phase III study earlier this year for the treatment of mild-to-moderate COVID-19 in an outpatient setting. The Roche study’s primary endpoint is time to alleviate or improve COVID-19 symptoms maintained for 24 hours. Data from that Phase III study is expected later this year.
The recently announced Phase II interim data showed AT-527’s active metabolite achieved target antiviral levels in the lungs. The company added that the bronchoalveolar lavage (BAL) study in healthy volunteers revealed plasma and intrapulmonary levels of AT-273 that exceeded the target concentration.
Jean-Pierre Sommadossi, founder and chief executive officer of Atea Pharmaceuticals, said they are encouraged by the data showing AT-527 achieved target drug levels in the lungs, which is the site of viral replication of COVID-19. The interim data not only provides confidence in the potential treatment from AT-527, but also supports the potential development of the asset as a COVID-19 prophylaxis medication. Additionally, he noted that the interim data from the ongoing Phase II study of AT-527 resulted in a rapid decline in viral load, which led to viral clearance.
“Impacting key sites of infection will be important in helping patients recover faster while minimizing virus transmission,” Sommadossi said in a statement.
AT-527 is seen as a potential rival for Gilead Sciences remdesivir, which was an early standard-of-care against COVID-19. Gilead Sciences remdesivir was the first antiviral drug to be approved by the FDA against COVID-19.
Remdesivir, which is sold under the trade name Veklury, was first granted EUA in May 2020 and later given full approval by the FDA in October. However, the drug came under intense scrutiny from healthcare agencies across the globe, including the World Health Organization, recommending against the drug in hospitalized patients. Last year, the WHO said there is no evidence that remdesivir improves survival and other outcomes in these patients.
In addition to the interim data from the Phase II study, Atea announced an amendment to its mid-stage study of AT-527 in hospitalized patients. The protocol amendments include changing the primary endpoint to virology, adding a Part B cohort comprised of up to 110 patients, and exploring alternative doses.
Janet Hammond, Atea’s chief development officer, said a multi-pronged treatment approach to COVID-19 is needed, particularly as a new wave driven by the Delta variant sweeps across the United States. Antiviral medications will become necessary to reduce the disease burden here and across the globe.
“We are very pleased with our results showing AT-527’s strong antiviral potential and we continue to advance multiple global clinical studies in parallel with our collaborator Roche, to provide further clinical evidence in support of AT-527 as an oral, potent, direct-acting antiviral treatment for COVID-19,” Hammond said in a statement.