A comprehensive global study of potential drugs to treat Covid-19 suggests that remdesivir – one of the few drugs available for the virus – may not be of any real benefit to sick patients. However, doctors at the forefront of treating severe cases advise caution when interpreting results.
“We already knew that in sick populations the results weren’t really changing,” said Dr. Ken Lyn-Kew, pulmonologist in the intensive care unit at National Jewish Health in Denver.
That doesn’t mean, however, that remdesivir – which received emergency approval from the Food and Drug Administration in May – isn’t useful against Covid-19.
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The new study, which included data from more than 11,200 people in 30 countries, is the result of the World Health Organization Solidarity process. It was published online on the preprint server on Thursday medRxivThis means that it has not been reviewed by experts.
Remdesivir wasn’t the only treatment given to patients in the study. Some were given hydroxychloroquine (which has since been shown to be ineffective in treating Covid-19), lopinavir (an antiviral drug used in HIV treatment), and interferon (another antiviral drug). Some received a combination of the drugs. Others only have one. Still others received no treatment.
The study found that remdesivir did not reduce deaths overall and did not help patients with severe Covid-19 get out of the hospital faster.
The latter finding contradicts a large study funded by the National Institutes of Health on the drug, which found remdesivir to reduce the time it took adults hospitalized with Covid-19 to get out of the hospital.
Dr. Andre Kalil, lead researcher for the NIH study at the University of Nebraska Medical Center, Omaha, said the solidarity study lacked some of the fundamentals critical to scientific research: “No data monitoring, no placebo, no double blindness, no diagnostic confirmation of infection.”
“Poor quality study design cannot be remedied by a large sample size, no matter how large,” Kalil told NBC News.
Outside experts also said it was no surprise that the drug did not seem to benefit sick patients. Remdesivir is an antiviral drug. Like Tamiflu for influenza, antivirals are generally more effective when given early in the disease.
“We knew that in sick populations, the results didn’t really change,” said Lyn-Kew. “This study only confirms that it is not a miracle drug.”
A potential stumbling block to early treatment with Remdesivir is intravenous administration. It cannot be prescribed in pill form for newly diagnosed patients to take at home. However, Gilead Sciences, which makes remdesivir, has begun studying the effects of an inhaled version of the drug. If safe and effective, it can be used at home before taking over the inflammatory process of the body.
This inflammatory process, and not the acute viral infection, is responsible for the more serious consequences of Covid-19. In theory, after this inflammation took over, an antiviral drug to reduce the amount of virus in the body would be minimally effective at best.
“An antiviral agent can be expected to produce diminishing returns,” said Cameron Wolfe, an infectious disease expert and associate professor of medicine at Duke University School of Medicine. People infected with Covid-19 generally go through an initial phase of infectivity that could be compromised by an antiviral agent.
“The second phase is much more anti-inflammatory,” said Wolfe. “It’s probably not surprising that an antiviral drug is less effective when you’re in the middle of this newly inflamed secondary phase.”
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Wolfe also expressed frustration that the WHO was preprinting the results, unlike an peer-reviewed study.
A preprint “was probably fine in January or February when we really had a public health emergency and wanted to get important information out quickly,” he said, adding, “We are now moving to an area that has the Changing standard of care through press release is a really dangerous precedent. “
“The highest quality data we’ve published everywhere still says remdesivir is effective,” said Wolfe.
“I’ll hang my hat on these dates every time.”