After more than a year and a half of an agonizing pandemic, researchers at Merck and Ridgeback Biotherapeutics have announced a successful oral antiviral treatment. The drug, called molnupiravir, prevents about half of COVID-19-associated hospitalizations. The data monitoring committee, which oversees clinical trials, stopped the trials because the evidence of efficacy was sufficiently persuasive — hospitalizations reduced by 50%, deaths by 100% — that they deemed it unethical to continue with a placebo-treated control group.
On Oct. 11, the sponsors requested emergency use authorization from the Food and Drug Administration. Merck expects to have more than 10 million courses of therapy available by the end of this year.
Molnupiravir (also called EIDD-2801) is a "prodrug," meaning it is metabolized in the body to the active molecule, which in turn inhibits replication of the viral RNA by interacting with a viral enzyme, causing an "error catastrophe," a profusion of mutations.
The promise of molnupiravir represents a new phase in the pandemic: an oral treatment of mild to moderate COVID-19 that markedly lowers the probability of serious illness or death. Perhaps we can now look forward to a new normal. Although experts predict COVID-19 will become endemic, with an oral, safe, and effective drug available, many sectors of the economy such as hospitality and travel should be able to return to near-normal, pre-pandemic operations.
Oral antiviral agents to treat COVID-19 are important and being developed by many companies — pharmaceutical giants Pfizer and Roche said they might be able to apply for emergency use authorization for their own drugs later this year — and complementary progress is also occurring on other fronts. If and when oral drugs are approved, they could be used in conjunction with "wearable " diagnostics, which were the subject of a fascinating research article published last month.
In the study, participants wore a wristband that measured real-time physiological signals such as heart rate, skin temperature and electrical activity, and movement. The participants were intentionally exposed to the H1N1 flu virus or human rhinovirus, and the data were collected both before and after exposure. Study participants reported daily symptoms, and researchers measured viral shedding.
By comparing the biometric data from the wearable devices before and after infection, the researchers could distinguish between infection and noninfection with 92% accuracy for influenza and 88% accuracy for rhinovirus. They could also distinguish between mild and moderate infection 24 hours prior to symptom onset with 90% accuracy for influenza and 89% accuracy for rhinovirus.
So, when your newfangled wristband tells you that you're probably infected, you pop an antiviral pill, and Bob's your uncle. But who knows when all of this will be reality.
In a world where vaccine hesitancy remains common, an oral antiviral drug, with or without wearable diagnostics, could help a lot. Yet vaccines should remain the mainstay to prevent severe COVID-19 and hospitalizations; the prevention of disease is always preferable to treating it.
Why? Well, like most drugs, molnupiravir is not a cure-all. The preliminary data indicate that it reduces hospitalizations by half, so the other half will remain a source of patient suffering, hospitalizations, and possibly long COVID. There are also practical considerations. For one thing, antivirals need to be administered shortly after symptoms begin. For Tamiflu, the anti-flu drug, treatment needs to begin within 48 hours after the onset of symptoms.
What's more, antivirals tend to be very expensive. The monoclonal antibody drug made by Regeneron, a combination of two antibodies, costs $1,250 per dose, while the GSK-Vir single antibody treatment is over $2,000 . (And both of these are administered intravenously or subcutaneously, which is another significant disadvantage.) The newer Hepatitis C drugs, which are given as pills, are far more expensive, about $40,000-95,000 for a 12-week course of therapy.
Thus, there are huge costs to society in relying solely on antivirals rather than vaccines.
This situation is not unique to COVID-19. The flu is similar in that although antivirals are useful in shortening and reducing the severity of the illness, the primary strategy is to prevent infection with annual vaccination.
The bottom line is that research and development on drugs and medical devices are making real, if slow, progress. The light at the end of the COVID-19 tunnel is growing brighter.
Henry I. Miller, a physician and molecular biologist, is a senior fellow at the Pacific Research Institute. Sheeva Azma, a freelance science writer, is the founder of science writing and digital communications company Fancy Comma, LLC .