Merck Slumps on Covid Pill’s Lower Efficacy, FDA Scrutiny
Merck Says Covid Pill Cuts Hospitalization, Death Risk by 30%
(Bloomberg) -- Merck & Co. shares sank after new data showed its Covid-19 pill was less effective than previously reported and U.S. regulators raised concerns about its safety and long-term effectiveness.
Merck’s latest trial results, reported Friday from a larger population than its initial study, show that its pill reduced the risk of hospitalization or death among adults with mild to moderate disease by 30%. That was less than a previous estimate of 48%.
Staff at the Food and Drug Administration, meanwhile, called the pill, molnupiravir, effective for individuals at increased risk for severe disease. But they raised questions about whether the treatment could cause birth defects, as well as bone and cartilage toxicity and genetic mutations. The staff also cited possible resistance to the drug, which occurs when viruses and bacteria evolve to blunt or defeat a drug’s mechanism of attack.
The documents published Friday by the FDA are meant to spur discussion in a meeting next week of advisers to the agency, which will then determine whether to authorize molnupiravir for emergency use.
Shares of Merck slid 3.8% on Friday as the drugmaker heads for its worst month since the start of the pandemic. Pfizer Inc., which is producing its own Covid pill that has shown to be more effective in early studies, rose 6.1%.
The news comes after the discovery of a new coronavirus variant in South Africa, described by scientists as very different from previous incarnations and of serious concern.
The latest Merck trial analysis includes data from all participants, the company said in a statement. Nine deaths were reported in the placebo group, and one in the group receiving the treatment.
Merck sought U.S. authorization for molnupiravir, also called Lagevrio, in October after a late-stage study showed it cut the risk of hospitalization or death by around 50% in high-risk patients. Pfizer’s Paxlovid has been submitted for review for use in the same population.
If authorized by regulators, the pills from Merck and Pfizer are likely to overtake infused drugs monoclonal antibodies from Regeneron Pharmaceuticals Inc. and Eli Lilly & Co. that are more expensive and harder to use.
Covid cases and hospitalizations are climbing after a slowdown in the summer’s delta-fueled surge. The seven-day average of infections rose 18% from a week earlier, and hospitalizations rose 6% over the same period, Centers for Disease Control and Prevention Director Rochelle Walensky said Monday.
‘Treatment-Inclined’
While vaccines and boosters continue to protect most who take them, the hesitant continue to be hospitalized and die of Covid at vastly higher rates. Although more than 59% of Americans are fully vaccinated, there are still 47 million eligible Americans and 12 million teenagers who aren’t.
Both Merck and Pfizer’s pills could expand treatment options for people who test positive for the virus, yet are only effective when taken in the earliest stages of the disease. Also, there are still questions about the drugs’ safety that will need to be addressed in the review process.
“We have experience with millions of doses of vaccine, but somehow there are some people who are vaccine-reluctant or vaccine-stubborn,” William Schaffner, a Vanderbilt University infectious disease professor, said in an interview. “On the other hand, they are open to treatment should they get sick, and of course that’s more hazardous, as neither of these drugs are 100% effective in preventing serious disease. But nonetheless there are some people who are much more treatment-inclined.”
Merck’s is the first Covid treatment referred to an advisory panel, according to the FDA. It works by introducing errors in genetic material, which some experts have said may affect growing human cells and raise the risk of birth defects, for example.
Merck’s pill will soon be followed by Pfizer’s, which reduced hospitalizations and deaths in high-risk patients by 89% in a study. It’s too soon to say which drug is better because of potential differences in the populations they were tested in, according to Bloomberg Intelligence analyst Sam Fazeli.
EU Permission
Regulators have already given permission for the the Merck drug, developed in collaboration with Ridgeback Biotherapeutics LP, to be used in emergency treatment of adults in the European Union. It hasn’t been formally authorized for sale.
Unlike infused drugs that are administered in hospitals or clinics, a five-day course of molnupiravir can be taken at home. The U.S. has paid about $700 per course of the drug, according to Fazeli, about a third of the cost of antibody therapy.
Merck and the FDA’s staff will each present data on molnupiravir to the panel, the Antimicrobial Drugs Advisory Committee, on Tuesday. There will also be public comment before a vote in the afternoon on whether to support authorization.
The agency isn’t obligated to follow the panel’s recommendations, though it typically does. A decision on clearance could come soon after the meeting concludes.
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