A huge, global study of potential drugs for the treatment of Covid-19 suggests that remdesivir – one of the few drugs available for the virus – may not provide any real benefit to the sickest patients. But doctors at the forefront of treating serious cases advise caution when interpreting the results.
“We already knew that in sicker populations, it did not really change the results,” said Dr. Ken Lyn-Kew, a pulmonologist in the critical care section of National Jewish Health in Denver.
This does not mean that remdesivir – which was granted an emergency use approval by the Food and Drug Administration in May ̵
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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’s Solidarity Trial. It was posted online Thursday on the preprint server withRxiv, meaning it is not peer-reviewed.
Remdesivir was not the only treatment given to patients in the trial. Some received hydroxychloroquine (which has since been shown to be ineffective in the treatment of Covid-19), lopinavir (an antiviral agent used to treat HIV) and interferon (another antiviral agent). Some were given a combination of the drugs. Others got only one. Still others received no treatment.
The trial showed that remdesivir generally did not reduce mortality and did not help patients with severe Covid-19 get out of the hospital faster.
The latter finding contradicts a large National Institutes of Health-funded trial of the drug, which showed that remdesivir reduced the time it took for adults hospitalized with Covid-19 to be discharged from the hospital.
Dr. Andre Kalil, a lead researcher for the NIH study at the University of Nebraska Medical Center in Omaha, said the Solidarity trial lacked some of the basic critical aspects of scientific research: “No data monitoring, no placebo, no double-blindness, no diagnostic confirmation of infection.”
“Poor quality survey design cannot be arranged with a large sample size, no matter how large it is,” Kalil told NBC News.
External experts also said it is no surprise that the drug did not appear to benefit the sickest patients. Remdesivir is an antiviral medicine. Like Tamiflu for influenza, antiviral drugs are generally more effective when given early in the course of the disease.
“We knew that in sicker populations, it didn’t really change the results,” Lyn-Kew said. “This study just reinforces that it is not a miracle cure.”
A possible obstacle to early treatment with remdesivir is that it is administered intravenously. It can not be prescribed in pill form for newly diagnosed patients to take at home. However, Gilead Sciences, which manufactures strapsivir, has begun investigating the effects of an inhaled version of the drug. If it is safe and effective, it can be used at home before the body’s inflammatory process takes over.
The inflammatory process rather than the acute viral infection is responsible for the more serious consequences of Covid-19. In theory, once an inflammation has taken over, an antiviral drug to reduce the amount of virus in the body would be minimally effective at best.
“It’s reasonable to expect an antiviral drug to have declining 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 can be affected by an antiviral.
“The second stage is much more hyperinflammatory,” Wolfe said. “It’s probably not surprising that if you’re in the middle of the newly inflamed secondary phase, an antiviral drug would have less of an impact.”
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Wolfe also expressed frustration that the WHO released the results as a pre-print as opposed to a peer-reviewed study.
A pre-print “was probably OK in January or February when we really had an emergency for public health and wanted to disseminate critical information quickly,” he said, adding: “We are moving to a space now where changing the standard of care by press release is a really dangerous precedent. “
“The highest quality data we’ve published anywhere still says belt straps are effective,” Wolfe said.
“I hang my hat on this data every time.”
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