Merck's COVID pill Lagevrio comes up short in household COVID exposure study

Initially hyped as a game-changing COVID-19 treatment, the shine was off Merck and Ridgeback’s oral antiviral Lagevrio (molnupiravir) even before it was authorized for use in the United States.

Nevertheless, the pill generated more than $6.6 billion in sales over its first five quarters on the market, despite mounting evidence of its limited effectiveness.

Another bit of confirmation came on Tuesday when Merck reported that Lagevrio did not provide a “statistically significant reduction” in the risk of COVID-19 following household exposure to the virus.

In the phase 3 MOVe-AHEAD trial, which observed more than 1,500 participants who were free of COVID-19 and lived with someone who was recently diagnosed with the virus, patients treated with Lagevrio were 23.6% less likely than those on placebo to develop COVID after 14 days.

While the findings were "scientifically interesting," Merck Research Laboratories president Dean Li, M.D., Ph.D., said in a statement, Lagevrio nevertheless did not meet the trial’s primary endpoint.

Merck had hoped to build a case for Lagevrio’s use as prophylactic treatment option. It is currently endorsed for those who have been infected and are at a risk of progressing to a severe form of COVID-19.

In October of 2021, there was much excitement over the first-of-its-kind pill when Merck and Ridgeback announced that it cut the risk of hospitalization and death in at-risk COVID patients by 50%.

In November, a day after the U.K. authorized use of molnupiravir, Pfizer said that its oral antiviral answer, Paxlovid, cut the risk of hospitalization by 89%. Then in December, the U.S. signed off on molnupiravir, but only after a divided FDA advisory committee voted 13-10 to recommend its use.

Six months before it was even authorized, the U.S. had bet big on molnupiravir’s potential, agreeing to pony up $1.2 billion for 1.7 million courses of the treatment.

Today, of the 2.9 million courses of Lagevrio delivered to the U.S., only 1.1 have been administered, according to the Department of Health and Human Services. Meanwhile, of the 12.1 million courses of Paxlovid delivered in the U.S., 8.1 million have been administered.

In July of last year, while the FDA decided to allow pharmacists to prescribe Paxlovid, the regulator didn’t extend the same privilege to Lagevrio.

Four months ago, a real-world study of Lagevrio in the U.K. showed that it did not reduce the risk of death or hospitalization in those who had been vaccinated. Then in November, Europe's National Institute for Health and Care Excellence (NICE) recommended against government coverage of Lagevrio, along with the use of four other COVID products.

In its fourth quarter earnings report, Merck projected sales of Lagevrio to reach $1 billion this year after they hit $5.7 billion last year.