Pfizer Inc and Merck & Co Inc announced on Wednesday new trials of their experimental oral antiviral drugs for COVID-19 as the race to develop an easy-to-administer treatment for the potentially fatal illness heats up, Reuters reports.
The new Pfizer's drug is designed to block the activity of a key enzyme that is needed for the coronavirus to multiply.
According to Pfizer, the latest mid-to-late-stage trial will enroll 1,140 non-hospitalized adults diagnosed with coronavirus infection who are not at risk of severe illness. Patients in the trial will be given Pfizer's pill, known as PF-07321332, and a low dose of ritonavir, an older medication widely used in combination treatments for HIV infection.
Merck said its new trial will study the experimental drug molnupiravir for the prevention of COVID-19 among adults in the same household as someone diagnosed with symptomatic coronavirus infection. Merck and partner Ridgeback Biotherapeutics are already conducting a late-stage trial of the treatment in non-hospitalized patients to see if it reduces the risk of hospitalization or death.
Molnupiravir is a type of antiviral designed to introduce errors into the RNA of the virus that eventually prevent it from replicating.
Rivals Pfizer and Merck, along with Swiss pharmaceutical Roche Holding AG, have made the most progress in developing what would be the first antiviral pill to treat, or possibly prevent, COVID-19.
It's worth noting that earlier in July, Pfizer began a different trial of PF-07321332 in adults with COVID-19 infection who are at high risk of becoming severely ill due to underlying health conditions such as diabetes. The company said it expects initial results from that study sometime this fall.