How effective was the drug in trials? So effective that an independent panel looked at some preliminary data and told Merck there was no reason to see those trials through to completion. The pill was obviously working.

Merck has been notably absent from America’s vaccine offensive against the virus, having seen its vaccine candidate go bust in trials earlier this year. But its effort to nuke the virus on the back end, after someone is already infected with it, looks like a smash success based on the data it released this morning. It partnered with a firm called Ridgeback Biotherapeutics to develop an antiviral called molnupiravir. An antiviral to treat COVID already exists, of course: That’s remdesivir, which was authorized for emergency use many months ago. But remdesivir’s effect on the progression of the disease is modest and it needs to be administered by a medical tech via IV.

Molnupiravir is a pill. And its effect isn’t so modest.

“I think it will translate into many thousands of lives being saved worldwide, where there’s less access to monoclonal antibodies, and in this country, too,” said Dr. Robert Shafer, an infectious disease specialist and expert on antiviral therapy at Stanford University…

For the research, the monitors looked at data through early August, when the study had enrolled 775 volunteers in the United States and overseas. For volunteers who received the drug, their risk of being hospitalized or dying fell 50 percent, without any concerning side effects, compared with those who received placebo pills, Merck said in a news release announcing the findings.

Seven percent of volunteers in the group that received the drug were hospitalized, and none of them died, compared with a 14 percent rate of hospitalization and death — including eight deaths — in the group that received the placebo.

The pill was offered in trials exclusively to unvaccinated people who’d already begun experiencing symptoms as many as five days earlier, giving the virus a considerable head start on generating a severe infection. Even so, no one who received the drug died. And it was effective against multiple variants, including Delta.

It’s Tamiflu for COVID, essentially — except it actually works. In light of Merck’s data, imagine how effective it might be at preventing severe illness if it were prescribed immediately after someone tested positive, within the first day or two of symptoms, instead of five days later. It could even be used as a prophylactic in theory to prevent or limit infection in someone who was exposed to the virus in a high-risk setting but isn’t yet symptomatic.

It’s not as effective as monoclonal antibodies, which cut hospitalizations and deaths by 70-85 percent, but antibody treatments are also administered via IV and therefore can’t be done at home. And they’re far more expensive than Merck’s drug:

Price of #covid19 drugs/vaccines:

Pfizer vaccine: $19.50/dose x 2 = $39 for primary series

Regeneron antibody drug: $2100/dose

Merck/Ridgeback's molnupiravir (if EUA'd): ~$700/course (US paying $1.2B for 1.7m courses) or $70/pill

— Meg Tirrell (@megtirrell) October 1, 2021

Just as the vaccines inspired by the pandemic represented a breakthrough, i.e. the use of mRNA to generate antibodies against a novel virus, the new therapeutic involves a breakthrough as well. Instead of attacking viral proteins, molnupiravir scrambles the invader’s genes to stop it from replicating. In other words, it hacks the virus.

Unlike vaccines or antibodies that target specific proteins on the surface of the virus, molnupiravir works by introducing genetic errors that garble the coronavirus’s genetic code. That means it may be more resistant to mutation, and may even work on other coronaviruses or RNA viruses.

“As a virologist, that’s one of the things I find particularly exciting,” Hazuda said. “Now, we’ve demonstrated the potential to have a drug that could work across multiple coronaviruses. I don’t think this is the last pandemic in our lifetime, and having something readily available that is active would be amazing.”

Millions of lives globally could be saved by a drug that cuts COVID hospitalizations by 50 percent. And I don’t just mean the lives of people who have COVID. More ICU capacity means more care for those with other critical illnesses, some of whom ended up dying because they couldn’t be seen by doctors in a timely way during this summer’s surge.

How soon will molnupiravir be available and how widely? That’s where things get sticky. Uncle Sam has already purchased 1.7 million courses, which is great but underwhelming when you remember that we’re still averaging more than 100,000 COVID cases per day. If the pill were available right now and everyone who tested positive received it, we’d run out in around two weeks. Merck can and will make more, of course, but they’re expecting to have “only” 10 million courses available by the end of the year. And not all of those courses are earmarked for the United States, needless to say.

All of which means we’re about to have another testy public debate over “COVID equity.” The WHO and some scientists here at home have decried America’s insistence on giving out boosters, believing that those doses would do more good being sent abroad to poor countries with low vaccination rates. The arrival of molnupiravir means we’re about to open a new chapter in that argument. If America is “hogging” vaccines for itself, the least it can do to make amends is be generous with therapeutics by sending the lion’s share of Merck’s drug abroad to help suffering people who haven’t had a chance to be vaccinated.

We’re also going to end up fighting over who should get priority for the available supply of molnupiravir here in the U.S. Should we do it the same way as we did the vaccines, with senior citizens getting first dibs? Should the unvaccinated be given special priority since they’re at higher risk of a severe case from COVID than the vaccinated are? If that’s what the feds decide, they’ll end up incentivizing vaccine holdouts to continue holding out, assuring them that they get to cut the line for treatment if they happen to get infected.

Maybe those concerns are overblown, though, since Merck isn’t the only pharma company with a promising antiviral in the pipeline. Hopefully we’ll end up in the same spot with therapeutics as we were with vaccines, with a tight supply for a few months and then suddenly more than we know what to do with.

I’ll leave you with Scott Gottlieb barely containing his enthusiasm about the Merck results. He’s a member of the board of Pfizer, a competitor, but a gamechanging drug is a gamechanging drug.

"This is a phenomenal result. This is a profound game-changer to have an oral pill that had this kind of effect, this magnitude of effect in patients who are at high-risk who are already symptomatic," says @ScottGottliebMD on news of $MRK's #covid19 antiviral study result. pic.twitter.com/2cfI3BFQUd

— Squawk Box (@SquawkCNBC) October 1, 2021