Keeping people at home is a priority
“We always believed antivirals, especially an oral antiviral, would be an important contribution to the pandemic,” Daria Hazuda, vice president of infectious diseases and vaccine discovery at Merck, tells the Washington Post. “Keeping people out of the hospital is incredibly important, given the emergence of variants and the continued evolution of the virus.”
Merck’s news comes on the heels of Pfizer’s announcement early last week that it had entered phase 2/3 clinical trials for a COVID antiviral it calls PF-07321332.
Pfizer’s drug candidate would be taken in combination with the antiretroviral HIV drug ritonavir to see if it could keep COVID from spreading to healthy trial participants living in the same household as someone with a confirmed infection, the company said in a statement.
The trial plans to enroll up to 2,660 people who will be randomly assigned to receive either the pill or a placebo twice daily for 5 to 10 days.
Meanwhile, Roche and Atea Pharmaceuticals announced positive early results for its own experimental antiviral, AT-527, in late June.
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Early data from phase 2 trials showed that in two days the pill reduced the viral load of COVID patients by 80% on average compared to placebo. However, the early analysis only involved data from 62 hospitalized, high-risk patients.
The Roche-Atea pill wound up clearing about 47% of patients within two weeks, making them completely COVID-free. By comparison, 22% of people taking a placebo were cleared of COVID in the same time frame.
Roche and Atea expect to announce more results from phase 2 and 3 trials later this year, the companies say.
The prospect of curbing COVID at home with a pill is cause for cautious celebration, Schaffner notes.
“Isn’t it great that we have at least three different firms working on three different drugs?” Schaffner says. “It’s like the Olympics. We want to see who gets there first, but we would like to see all three of them be successful.”
Merck — which is developing the pill with Ridgeback Biotherapeutics of Miami — did not say which patients it would ask the FDA to approve for the treatment. Initially, that group may be limited to patients who are eligible to receive monoclonal antibody treatments, possibly older people, and those with medical conditions that put them at high risk for poor outcomes from COVID-19 infection. But experts note that they expect the drug to eventually be used in many people who test positive for the virus, The Times reported.