Health regulators in the United States have authorised the first oral pill against COVID-19, a Pfizer drug that users will be able to take at home to head off the worst effects of the coronavirus.
The long-awaited milestone was announced on Wednesday by the US Food and Drug Administration (FDA). The approval comes as coronavirus cases spike globally, including in the US, and health officials warn of a tsunami of new infections from the Omicron variant that could overwhelm hospitals.
Data from Pfizer’s clinical trial showed its antiviral regimen was 90 percent effective in preventing hospitalisations and deaths in patients at high risk of severe illness. Recent lab data suggests the drug retains its effectiveness against Omicron.
The drug, Paxlovid, is a faster, cheaper way to treat early COVID-19 infections, though initial supplies will be extremely limited. All of the previously authorised drugs against the disease require an IV or an injection.
“The efficacy is high, the side effects are low and it’s oral. It checks all the boxes,” said Dr Gregory Poland of the US-based Mayo Clinic. “You’re looking at a 90 percent decreased risk of hospitalisation and death in a high-risk group — that’s stunning.”
President Joe Biden welcomed the approval of the pill later on Wednesday, saying that the US will have 250,000 treatment courses in January. “With today’s action, we add the first-ever oral treatment to our nation’s medicine cabinet and take a significant step forward in our path out of the pandemic,” Biden said in a statement.
The FDA said it authorised the drug for emergency use for the treatment of mild-to-moderate disease in adults and pediatric patients of 12 years of age and older weighing at least 40kg (88 pounds), who are at high risk for progression to severe COVID-19. That includes older people and those with conditions like obesity and heart disease.
“This authorization provides a new tool to combat COVID-19 at a crucial time in the pandemic as new variants emerge and promises to make antiviral treatment more accessible to patients who are at high risk for progression to severe COVID-19,” Patrizia Cavazzoni, director of the FDA’s Center for Drug Evaluation and Research, said in a statement.
The drug is available by prescription only and should be initiated as soon as possible after the diagnosis of COVID-19 and within five days of symptom onset, the agency said.
Pfizer’s drug is part of a decades-old family of antiviral drugs known as protease inhibitors, which revolutionised the treatment of HIV and hepatitis C. The drugs block a key enzyme which viruses need to multiply in the human body.
The company said it was ready to start immediate delivery in the US and raised its production projections to 120 million courses of treatment from 80 million in 2022.
The US government’s contract for 10 million courses of the Pfizer drug is priced at $530 per course.
Pfizer’s pill comes with its own challenges.
Patients will need a positive COVID-19 test to get a prescription. And Paxlovid has only proven effective if given within five days of symptoms appearing. With testing supplies stretched, experts worry it may be unrealistic for patients to self-diagnose, get tested, see a physician and pick up a prescription within that narrow window.
“If you go outside that window of time I fully expect the effectiveness of this drug is going to fall,” said Andrew Pekosz, a Johns Hopkins University virologist.
A rival pill from Merck & Co, which is under review by the FDA, has shown lower efficacy compared with Pfizer’s treatment. Merck’s drug, molnupiravir, reduced hospitalisations and deaths in its clinical trial on high-risk patients by about 30 percent.
The pills from both Pfizer and Merck are expected to be effective against Omicron because they do not target the spike protein where most of the variant’s worrisome mutations reside.
Most health experts have said vaccination remains the best way to protect against COVID-19. But with roughly 40 million American adults still unvaccinated, effective drugs will be critical to blunting the current and future waves of infection.