GOVERNMENT health advisers on Tuesday weighed the benefits and risks of a closely watched drug from Merck that could soon become the first U.S.-authorized pill for patients to take at home to treat COVID-19.

The Food and Drug Administration (FDA) asked its outside experts whether the agency should authorize the pill, weighing new information that it is less effective than first reported and may cause birth defects. The panel’s recommendations aren’t binding but often guide FDA decisions.

If authorized, Merck’s pill would be the first that doctors could prescribe for patients to take on their own to ease symptoms and speed recovery, a major step toward reducing hospital caseloads and deaths. The drug, molnupiravir, is already authorized for emergency use in the U.K.

Given the ongoing threat, the FDA is widely expected to approve emergency use of Merck’s pill. But new data released last week painted a less compelling picture than when the company first publicized its early results in October.

Last week, Merck said final study results showed molnupiravir reduced hospitalization and death by 30 percent among adults infected with the coronavirus, when compared with adults taking a placebo.

That effect was significantly less than the 50 percent reduction it first announced based on incomplete results.

FDA scientists said Tuesday the reasons for the difference were unclear, but appeared to be due to higher-than-expected hospitalizations among patients taking the drug during the second half of the study. Molnupiravir’s effectiveness is a key consideration as panel members weigh whether to recommend the drug and for whom.

Another question is whether pregnant women or women of child-bearing age should avoid the drug.

FDA scientists said Tuesday that company studies in rats showed the drug caused toxicity and birth defects in the skeleton, eyes and kidneys. Taken together, FDA staffers concluded the data “suggest that molnupiravir may cause fetal harm when administered to pregnant individuals.”

Regulators said they are considering barring molnupiravir’s use during pregnancy or warning against it but leaving it as an option in rare cases.

A rival drug from Pfizer is close behind and is also under review. Pfizer’s drug is part of a decades-old family of antiviral pills known as protease inhibitors, a standard treatment for HIV and hepatitis C.

(SD-Agencies)