The antiviral drug remdesivir succeeded in a clinical trial, according to preliminary results released Wednesday, raising hopes it could become the first approved treatment for COVID-19.
Dr Anthony Fauci, chief of the US National Institute of Allergy and Infectious Diseases (NIAID) that released the study and a top adviser on President Donald Trump's White House Coronavirus Task Force, said the result was a strong "proof of concept" for the drug.
The NIAID study observed more than 1,000 patients hospitalized with the coronavirus who were randomly given either remdesivir or a placebo in a controlled trial. Patients taking remdesivir recovered 31 percent faster than those taking the placebo, the study found.
"Although a 31 percent improvement doesn't seem like a knockout 100 percent, it is a very important proof of concept because what it has proven is that a drug can block this virus," Fauci said at the White House.
The typical patient who took remdesivir recovered in 11 days, while the typical patient in the placebo group recovered in 15 days.
Of the patients taking remdesivir, 8 percent died, compared with 11.6 percent of those in the placebo group, though the difference wasn't found to be statistically significant.
"Certainly it's positive, it's a very positive event," Trump said of the results.
The Food and Drug Administration will likely issue an emergency approval for remdesivir, The New York Times reported, citing a senior administration official.
Also on Wednesday, Pfizer said that testing of its coronavirus vaccine could start next week and could be ready by the fall.
NIAID said more information from the trial would be published in a forthcoming report.
Gilead's remdesivir isn't yet licensed or approved in the US or anywhere else in the world.
Remdesivir, which is given as an IV infusion, hasn't previously been approved to treat any diseases although it showed some promise when it was tried on Ebola patients several years ago.
In China, a separate trial of remdesivir did not find a meaningful benefit when compared with a placebo, according to results published Wednesday in the medical journal Lancet.
"Unfortunately, our trial found that while safe and adequately tolerated, remdesivir did not provide significant benefits over placebo," said the lead investigator of the new study, Dr Bin Cao of the China-Japan Friendship Hospital and Capital Medical University in Beijing.
That study was ended early because of the difficulty in finding enough COVID-19 patients to enroll in China, the researchers said.
Given that that study didn't reach full enrollment, the results are "inconclusive", said John David Norrie, a professor at the University of Edinburgh, in an accompanying commentary.
Gilead Sciences, the company that developed remdesevir, also released data Wednesday from its own trial of five-day and 10-day regimens of remdesivir in 397 patients with severe forms of COVID-19.
That study did not compare patients who got the drug with those who were given a placebo, making the results more difficult to interpret.
Merdad Parsey, Gilead's chief medical officer, said the results complemented the NIAID's placebo-controlled trial and were intended to help figure out the right dose for patients. The trial generated similar results for patients treated with the five-day course and those treated with the 10-day course, Gilead said.
"The study demonstrates the potential for some patients to be treated with a 5-day regimen, which could significantly expand the number of patients who could be treated with our current supply of remdesivir," Parsey said in a statement.
Using a five-day course could effectively double the number of patients who could be treated with the available supply of remdesivir. The company said that it was already ramping up manufacturing capacity, planning to produce more than 1 million courses by the end of the year.
