Merck COVID-19 pill effective but safety questions remain, says FDA

U.S. federal health regulators are out with their analysis of Merck’s experimental COVID-19 pill, ahead of a public meeting next week, saying it is effective against the virus.

However, there remain some questions about the pill’s safety.

The review flagged risks of toxicity to developing fetuses and other potential problems in pregnant people, after birth defects were identified in studies of the pill in animals.

The U.S. Food and Drug Administration is now asking its independent advisers if the drug’s benefits outweigh the risks and if its use should be restricted for some people.

The agency isn’t required to follow the group’s advice.

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Should the group of experts and academics say the drug could be made available in certain cases, the FDA says the pill would carry warnings. Doctors would still have the option to prescribe it in certain cases where its benefits could outweigh its risks for patients.

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

Other side effects were mild and rare, with about two per cent of patients experiencing diarrhea.

Regulators have also noted Merck collected far less safety data overall on its drug than was gathered for other COVID-19 therapies. Additionally, the FDA flagged a concern Merck’s drug led to small changes in the coronavirus’ signature spike protein, which it uses to penetrate human cells. Theoretically, the FDA cautioned, those changes could lead to dangerous new variants.

All COVID-19 drugs currently authorized by the FDA require an injection or IV and can only be given by health professionals. If authorized, Merck’s drug would be the first that people in Canada and the U.S. could take at home to ease symptoms of COVID-19 and speed recovery.

The pill is already authorized for emergency use in the U.K.