Pfizer and Merck & Co announced new trials for their new experimental oral antiviral drugs for Covid-19. The companies are looking to develop an easy-to-administer treatment for the disease.
Pfizer said that its trial will enrol 1,140 non-hospitalised adults diagnosed with coronavirus infection who are not at risk of severe illness. The patients in the trial will be given the experimental pill and a low dose of ritonavir, an older medication widely used in combination treatments for HIV infection. Pfizer’s pill, known as PF-07321332 is designed to block the activity of a key enzyme that is needed for the coronavirus to multiply.
The pharmaceutical giant began a different trial of PF-07321332 in July, in adults with Covid-19 infection who are at high risk of becoming severely ill due to underlying health conditions. The company expects initial results from the study in autumn. If the trial is successful, Pfizer said it would file for a potential emergency use authorisation by the fourth quarter.
Meanwhile, Merck said its new trial will study the experimental drug molnupiravir to prevent Covid-19 among adults in the same household as someone diagnosed with symptomatic infection. The drug is a type of antiviral designed to introduce errors into the RNA of the virus that eventually prevents it from replicating. The company and its partner Ridgeback Biotherapeutics are already conducting a late-stage trial of the treatment in non-hospitalised patients.
In June, Merck said that the US government agreed to pay around $1.2 billion for 1.7 million courses of molnupiravir, if proven to work, and if authorised by regulators. The company is expected to file for US emergency use authorisation in the second half of 2021 at the earliest. Early trial results for molnupiravir yielded promising results, and experts believe it could help cut back on the time that infected individuals remain positive for the virus.