Atea Pharmaceuticals’ antiviral has failed another COVID-19 trial, but the biotech still holds out hope the candidate has a future in hepatitis C.
The oral nucleotide polymerase inhibitor bemnifosbuvir failed to show a significant reduction in all-cause hospitalization or death by Day 29 in a phase 3 trial of 2,221 high-risk patients with mild to moderate COVID-19, missing the study’s primary endpoint. The trial tested Atea's drug against placebo.
Atea’s CEO Jean-Pierre Sommadossi, Ph.D., said the biotech was “disappointed” by the results of the SUNRISE-3 trial, which he attributed to the ever-changing nature of the virus.
“Variants of COVID-19 are constantly evolving and the natural history of the disease trended toward milder disease, which has resulted in fewer hospitalizations and deaths,” Sommadossi said in the Sept. 13 release.
“In particular, hospitalization due to severe respiratory disease caused by COVID was not observed in SUNRISE-3, in contrast to our prior study,” he added. “In an environment where there is much less COVID-19 pneumonia, it becomes more difficult for a direct-acting antiviral to demonstrate impact on the course of the disease.”
Atea has struggled to demonstrate bemnifosbuvir’s COVID potential in the past, including in a phase 2 trial back in the midst of the pandemic. In that study, the antiviral failed to beat placebo at reducing viral load when tested in patients with mild to moderate COVID-19.
While the study did see a slight reduction in higher-risk patients, that was not enough for Atea’s partner Roche, which cut its ties with the program.
Atea said today that it remains focused on exploring bemnifosbuvir in combination with ruzasvir—a NS5B polymerase inhibitor licensed from Merck—for the treatment of hepatitis C. Initial results from a phase 2 study in June showed a 97% sustained virologic response rate at 12 weeks, and further top-line results are due in the fourth quarter.
Last year saw the biotech turn down an acquisition offer from Concentra Biosciences just months after Atea sidelined its dengue fever drug after deciding the phase 2 costs wouldn’t be worth it.