The Atlanta Journal-Constitution
Antiviral pill shows promise in fighting virus
Molnupiravir, an antiviral pill being developed by Merck & Co., has been touted as a potential game-changer in the fight against COVID-19. The experimental medication was shown to reduce the risk of hospitalization or death by about half in a late-stage study of adults with mildto-moderate cases. The promise of a drug that patients can easily get and take at home has prompted some governments to order supplies even before regulators have decided whether to approve its use.
What is molnupiravir?
It’s the chemical name for a medicine originally developed to treat influenza that’s given orally in a capsule. It inhibits replication of SARS-COV-2, the coronavirus that causes COVID19, by a mechanism known as “lethal mutagenesis.” In simple terms, it causes the machinery that reproduces the virus’ genetic material to make mistakes, thereby rendering the copies defective. The drug was discovered at Emory University and is being developed by Kenilworth, New Jersey-based Merck and Miami-based Ridgeback Biotherapeutics LP.
How effective is it?
Interim analysis of data from a randomized trial found that it cut the risk of hospitalization by about 50%, Merck said in an Oct. 1 statement. Of 385 patients who got the drug, 28 (7.3%) were hospitalized, compared with 53 of 377 (14.1%) who got a placebo. Through day 29, no deaths were reported in patients who received molnupiravir, but eight died in the placebo arm. The study was relatively small, and further research is required. But results were so encouraging that Merck and Ridgeback, in consultation with independent trial monitors and the U.S. Food and Drug Administration, halted the trial and began the process of gaining regulatory clearance. The company said at a conference in September that early research showed molnupiravir can thwart the most common SARSCOV-2 variants, including delta and gamma.
How is it different from other drugs?
Gilead Sciences Inc.’s antiviral remdesivir, as well as monoclonal antibodies, are administered via an intravenous infusion. This is usually done in a hospital or a clinic, where infected people risk transmitting the virus to medical staff and other patients. Molnupiravir’s main advantage is that it’s taken as a pill, enabling patients to be treated at home. It’s also likely to be cheaper: A fiveday course of molnupiravir will cost about $700 per patient — a third of the cost of a monoclonal antibody treatment, according to the New York Times. Safe, well-tolerated, affordable and easy-to-administer antivirals are ideal treatments because they directly counter the virus, limiting its damage to the body and the duration of illness. Steroids and blood thinners that have been shown to improve survival in hospitalized patients don’t directly fight the virus; they prevent a worsening of COVID-19 symptoms.
How was it administered?
Molnupiravir was taken orally every 12 hours for five days by adults with mild-to-moderate COVID19. Studies are still underway to determine the most effective regimen. A study earlier this year showed molnupiravir had little effect when it was given to patients already hospitalized with severe disease. One study is testing whether it can be used to prevent SARS-COV-2 spreading in households in which one or more members have COVID-19.
Are there side effects?
Interim analysis found no increased incidence of adverse events. Only 1.3% of participants taking molnupiravir quit the therapy due to an adverse event, compared with 3.4% in the placebo group. Still, molnupiravir will need to be assessed in a much larger group of patients to properly determine its safety. People involved in the trial were instructed to abstain from heterosexual sex or use contraception. While this is routine practice with some other medicines, such as cancer chemotherapy, it suggests that molnupiravir has the potential to cause birth defects should someone become pregnant.