The European Medicines Agency (EMA) and the UK’s Medicines and Health Regulatory Authority (MHRA) have already granted provisional approval for adults who do not need oxygen support and are at risk of their disease worsening. The EMA advised against use during pregnancy for in women who plan to get pregnant and said that breastfeeding should be stopped when the treatment begins.

If the FDA approves the drug, which will be supplied in capsule form, it would be the first oral antiviral treatment to fight Covid-19. It must be taken within five days of the start of symptoms, and the total course recommended by Merck calls for taking four pills twice a day for five days.

Some members of the review panel said they were hesitant about recommending Lagevrio, especially as Merck had reduced its calculation of the treatment’s efficacy in preventing severe disease or death from 50% when it originally filed the EUA application, to 30%. The last US trial, conducted between August and October 2021, showed that among the 709 people in the molnupiravir group, 48 were hospitalized and one died. In the 699-member placebo group, there were 68 hospitalizations and nine deaths.

According to the journal ScienceNews, the panel’s uncertainty pertained not just to the efficacy figures but also to who should get the treatment it, noting that the list of those who should not get it was longer than those for whom most experts would recommend it. As animal studies have have indicated that molnupiravir might interfere with bone growth, pregnant women, children and adolescents would probably not be offered the treatment.

Other panelists reportedly queried whether the drug could lead to potentially dangerous mutations of the coronavirus. All in all, those voting for an EUA stressed that there are as yet no good remedies for people with mild to moderate Covid-19, so that even with its drawbacks, temporary use of Merck’s candidate could be justified. Most members said they hoped the drugmaker would be asked to continue gathering safety data.

The FDA is expected to make its decision shortly, potentially before Pfizer’s oral antiviral to treat Covid is reviewed by the advisory panel. A date for the review has not been announced. The US government has already agreed to buy 3.1 million courses of molnupiravir / Lagevrio for $2.2 billion, or around $700 per course of treatment. Additionally, Merck – as well as Pfizer – -has contracted with the international Medicines Patent Pool to make the drug available to poorer countries.

Merck has already begun producing molnupiravir at risk and expects to produce 10 million courses of treatment by the end of 2021, followed by at least 20 million courses to in 2022. Pfizer recently announced it would increase production of its oral treatment even before winning an EUA. The New York drugmaker has reported efficacy of 89% for its Covid candidate Paxlovid.

Author: Dede Williams, Freelance Journalist