On Wednesday, the FDA issued an Emergency Use Authorization for Pfizer’s antiviral drug treatment Paxlovid for use against COVID-19. Data from clinical trials indicated that when taken within five days after the onset of symptoms, the pill is 88% effective in reducing the chance of severe illness resulting in hospitalization. And, because the drug is available as a pill which is taken twice a day for five days, it’s not just a treatment that can be administered in a clinical setting. This EUA extends to at-home care.

Pfizer says that it is “ready to start immediate delivery in the U.S.” That includes delivery of the 10 million doses that have been pre-purchased by the U.S. government.

The drug is authorized for the use by those age 12 and older who are suffering mild to moderate symptoms, and who have tested positive for COVID-19. As the drug becomes available, the focus will be getting the drug to those most in danger of severe illness, but if the record of effectiveness and safety from the trials holds up in real-world tests against omicron and other variants, Paxlovid could easily become the standard of treatment. Pfizer reports that it has ramped up production and hopes to have enough for 80 million to 120 million courses of treatment in 2022.

The timing of this release could have been better—because earlier availability is always better. But it certainly could have been worse. As the U.S. is facing a surge of omicron cases, an at-home pill that cuts the rate of hospitalization to one-tenth of what it might have been could be just the medical miracle the nation needed.

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            Wednesday, Dec 22, 2021 ·  9:49:34 PM +00:00

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      Mark Sumner
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When pharmacies across the nation will actually have Paxlovid available to dispense isn’t quite clear. However, “immediately” may mean exactly that in this case. The Washington Post reports that “tens of thousands of pill packs” of the drug were waiting in a Memphis, ready to go into trucks and planes as soon as the EUA was announced. Each pill pack contains 30 pink tablets of Paxlovid, which equals a five-day course of treatment.

With case counts heading up in a hurry, it’s desperately needed. Even if those who are vaccinated and boosted have a low rate of severe illness, such breakthrough infections do occur. For the unvaccinated, there is so far mixed evidence that the lightning-fast spread of the omicron variant comes with any benefit in the forms of a milder disease. Rates of severe illness seem to be almost identical between omicron and delta in South Africa. However, a study out of Scotland suggests omicron produced only about one-third of the hospitalized cases when compared to earlier variants.

Even so, the high rate of contagion could more than outweigh any reduced rate of severe illness. Already U.S. news is full of reports of localized hospital overcrowding, delayed procedures, and an increasing rate of dropouts from overworked staff.

If Paxlovid can significantly impact the number of people going to the hospital, it can help prevent overcrowding of ICUs and hospital beds. Pushing down the occupancy rate of ICUs in particular could have a large impact on the rate of deaths as the U.S. meets the omicron surge. It might not turn a tsunami into a ripple, but it could prevent health care systems from facing drastic overcrowding, especially if targeted to areas under stress.

Despite Pfizer’s announced increases in production, the pills are expected to remain in short supply well into 2022. Manufacturing is complex, and creating a new batch takes months. The cost of a course of treatment is $530, but the government is expected to make the pills free to patients, as they have done with vaccines. 

In addition to U.S. regulators, the pill was approved earlier this week by  he European Medicines Agency (EMA); 2.75 million courses of treatment have been ordered by the U.K.

In addition to Paxlovid, there are three other potential treatments that have recently been in the news, one of which should be up for FDA approval shortly.

One of these is another antiviral pill, molnupiravir, manufactured by Merck. The FDA is widely expected to approve the use of molnupiravir within the next week. However, while the efficacy of the drug was good in initial Phase 1 testing, more extensive testing dropped that efficacy to only around 30%. A one-third reduction in severe illness is not nothing, and molnupiravir will certainly be administered, especially when other options aren’t available. 

The second new treatment is a new formulation of monoclonal antibodies from AstraZeneca. Other monoclonal antibodies have lost much of their effectiveness against omicron, but Evusheld has a different purpose. It’s specifically targeted at those who are immunocompromised in a way that makes them unable to take the vaccines, or prevents the vaccines from having an immune-stimulating effect. Evusheld is intended as a prophylaxis. That is, this is a preventive treatment, taken by people with immunological conditions, before they get sick.

Finally, there’s fluvoxamine, a drug which is already in wide use against depression and OCD. Like many existing drugs, fluvoxamine got a second look as a possible COVID-19 treatment. In this case, the drug’s anti-inflammatory effects recommended it for study. In one of those studies, fluvoxamine appeared to be spectacularly effective, raising great hopes for the treatment, but in two other trials that benefit seemed to evaporate. The FDA continues to recommend that “there is insufficient evidence for the COVID-19 Treatment Guidelines Panel to recommend either for or against the use of fluvoxamine for the treatment of COVID-19.” However, more trials are ongoing.