- Merck & Co.’s COVID-19 pill Lagevrio failed in a large clinical trial to prevent infections following household exposure to someone recently diagnosed with the disease, the drugmaker said Tuesday.
- In a study of over 1,500 adults, Lagevrio reduced the risk of getting COVID from a household exposure by 23.6% compared to placebo, a difference that did not meet the trial’s bar for success. The results followed similar data for Pfizer’s antiviral pill Paxlovid, which also failed to prevent household spread of the virus.
- Lagevrio is one of three antiviral treatments for COVID currently available in the U.S., but its use is expected to decline this year. Merck also sees potential for the pill as a treatment for respiratory syncytial virus and recently began a mid-stage study in healthy volunteers.
Lagevrio stands alongside Pfizer’s Paxlovid and Gilead’s Veklury as still-available COVID-19 treatments. Changes in coronavirus strains, by contrast, forced Regeneron, Eli Lilly and AstraZeneca to withdraw their antibody treatments due to their decreased efficacy against new variants.
Lagevrio generated about $5.7 billion in sales last year for Merck, but like other COVID treatment and vaccine makers, the company predicts sales of Lagevrio to ebb this year. Merck forecast only $1 billion in revenue from the pill in 2023, following similar scaled-back forecasts by Pfizer and Moderna.
Merck’s Phase 3 study evaluated Lagevrio in people who lived in the same household as someone who tested positive for the virus and showed at least one symptom of COVID. They were given Lagevrio every 12 hours for five days and tested for the virus for 14 days.
Merck did not release detailed data from the study. It plans to release full results later at a scientific meeting or in a publication.
While the study failed to prove the oral drug as a preventive option, Merck still sees potential for Lagevrio, including in infections other than COVID.
“We remain focused on our ongoing efforts to bring Lagevrio as treatment to appropriate high-risk patients with COVID-19 where its use is authorized or approved, as well as to further study the ways it may benefit patients with other infectious diseases, such as RSV,” said Merck's research chief, Dean Li, in the company’s statement.
RSV has been a major target for vaccine makers, with Pfizer and GSK seeking U.S. approvals and Moderna not far behind. AstraZeneca and Sanofi, meanwhile, are awaiting an FDA decision on their antibody treatment.
Those advances have not removed the need for further research, though. In November, Merck started a small mid-stage study evaluating Lagevrio as a treatment against RSV.