The Food and Drug Administration on Friday cleared an experimental drug from Gilead for emergency use in treating COVID-19, acting quickly following announcement on Wednesday of encouraging results from a crucial government-run study.
Results from the study, which was led by the National Institutes for Allergy and Infectious Diseases, showed treatment with remdesivir led to faster recoveries among patients hospitalized with COVID-19 than did placebo. Fewer patients given Gilead's drug died than in the placebo group, although the difference was not large enough to be considered statistically significant.
The emergency use authorization, or EUA, granted by the FDA is not equivalent to a standard drug approval, but it's a major milestone for a drug that's consistently been among the top treatment prospects for COVID-19, the disease caused by the new coronavirus.
Unlike regular approvals, an EUA is only effective for as long as the relevant emergency declaration is in place, and requires less supporting clinical evidence.
"Based on the totality of scientific evidence available to FDA, it is reasonable to believe that remdesivir may be effective in treating COVID-19," wrote Denise Hinton, the FDA's chief scientist in a letter to Gilead authorizing remdesivir.
That evidence includes results from the NIAID study, which was viewed by many as the key test of remdesivir's potential effectiveness, as well as data from a Gilead-run trial that were also announced on Wednesday. Gilead's study lacked a placebo control group, comparing instead five days of treatment with remdesivir to 10.
Taken together, the findings are the strongest sign yet that an antiviral drug can help patients with COVID-19 recover and, possibly, ease some of the strain experienced by hospitals across the U.S. and the world.
But many questions about the drug's safety and effectiveness still aren't answered, and the benefit shown by the NIAID study is, at best, modest. Among treated patients, the median time to recovery was 11 days versus the 15 days observed among those receiving placebo.
Only topline data was disclosed by NIAID Wednesday, meaning crucial information, such as which patients benefited most, is not yet known.
In comments at the White House Wednesday, NIAID director Anthony Fauci said the results, while an "important proof of concept," are only a first step to building a better toolkit of treatments for COVID-19. On its own, remdesivir won't change the course of the pandemic, which will ultimately require a safe and effective vaccine to be contained.
The FDA's authorization of remdesivir is the second time the FDA has cleared a drug for emergency COVID-19 use. At the end of March, the agency gave a similar nod to two variants of the malaria pill hydroxychloroquine, permitting the federal government to move supplies of the drug from national stockpiles to hospitals. Use of the pills was restricted, however, to only those patients who couldn't join a clinical trial.
The authorization was highly controversial, given the scant and conflicting clinical evidence supporting the hydroxychloroquine's use in treating COVID-19 symptoms. The topic also became political, as President Donald Trump frequently touted hydroxychloroquine's benefits in press conferences starting in mid-March.
No randomized, placebo-controlled study had proven hydroxychloroquine effective, as the NIAID study has seemed to do for remdesivir.
EUAs are typically given to tests and other diagnostics, or to healthcare equipment like ventilators. But there are a few examples in the past of authorizations granted to drugs, such as the agency's 2001 decision to clear doxycycline for use against anthrax.
Under the EUA for remdesivir, the U.S. government will control distribution of Gilead's limited drug supply — some 1.5 million individual doses that the company has said it will donate. That's enough for 140,000 treatment courses of 10-day dosing, but data from Gilead's study support the use of a 5-day regimen, which would stretch supplies further.
In a statement, the company said the U.S. government will prioritize sending the drug to hospitals in U.S. cities that are hardest-hit by COVID-19 cases.
For Gilead, the EUA is only the first step. On Thursday, company CEO Daniel O'Day said Gilead's goal is to obtain a full approval for remdesivir, and hinted at ongoing discussions with the FDA regarding a drug application submission.
Regulators in Europe are already reviewing data on remdesivir, as well, ahead of potentially granting clearance.
In the meantime, Gilead is massively ramping up production of the drug in anticipation of overwhelming demand. The drugmaker expects it can produce enough drug for 1 million treatment courses by the end of the year.
To do so, Gilead is investing as much as $1 billion in manufacturing and clinical development, a hefty sum that's raised questions on Wall Street about how much Gilead plans to charge for the drug.
On a conference call Thursday, O'Day would say only that the company plans to be "very thoughtful" about ensuring access to the drug globally.
Should it choose to profit, Gilead will likely be judged harshly and could potentially face blowback from the public and the U.S. government, which is already at odds with the company over patents on a HIV drug.