FDA Claims Merck’s COVID-19 Pill Effective, But Will Be Reviewed

US health authorities reported that Merck’s experimental COVID-19 pill is effective against the virus, but that outside expert opinion will be sought on risks among pregnant women, such as possible birth defects and other problems.

The Food and Drug Administration (FDA) released its review of the pill ahead of a public meeting next week where academic and other experts will weigh in on its safety and efficacy. The agency is not obligated to follow the group’s advice.

FDA scientists said their review identified several potential risks, including possible toxicity and birth defects. Given those risks, the FDA will ask its advisers if the drug should be avoided during pregnancy or if it might be available in certain cases.

In that case, the FDA said the pill would carry warnings about its risks during pregnancy, but doctors would still have the option of prescribing it in certain cases where its benefits could outweigh the risks to the sick.

Given the safety concerns, the FDA said Merck agreed that the drug would not be used in children.

In addition, the FDA raised concerns that Merck’s drug causes small changes in the spike protein characteristic of the coronavirus, which it uses to penetrate human cells. In theory, the FDA warned, those changes could lead to dangerous new variants.

Regulators also noted that Merck collected far less overall safety data on its new drug than it did for other COVID-19 therapies.

The FDA will ask its independent advisers to discuss all of those issues and then vote on whether the pill’s overall benefits outweigh its risks.

All coronavirus drugs currently authorized by the FDA require an injection or an intravenous line, which limits their use because they can only be applied by healthcare professionals.

If licensed, Merck’s drug would be the first drug that patients could take at home to ease symptoms and speed recovery. The pill is already licensed for emergency use in the UK.

The meeting marks the first time regulators have publicly reviewed a new COVID-19 drug, reflecting intense interest and scrutiny for a pill that could soon be used by millions of Americans.

The drug, molnupiravir, has been shown to significantly reduce the rate of hospitalizations and deaths among people with mild to moderate coronavirus infections.

Merck’s drug uses a novel approach to combat COVID-19: It inserts tiny mutations into the genetic code of the coronavirus to the point where it cannot reproduce, but that genetic effect has raised concerns that, on rare occasions, the drug can cause birth defects or tumors.