Early research shows that an experimental treatment for the coronavirus may help very sick patients improve their breathing, though experts caution that more studies are needed before the drug, remdesivir, can be recommended.

The research, published Friday in The New England Journal of Medicine, looked at 53 coronavirus patients who had been given remdesivir through what’s called "compassionate use."

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In a majority of the patients — 68 percent — doctors were able to reduce the amount of oxygen support needed. What's more, 17 of 30 patients who'd been on ventilators were able to come off of those machines. That's important because COVID-19 patients who need to be put on ventilators appear to be more likely to suffer long-term health consequences, and may have worse outcomes.

"If you go on a ventilator there is roughly only a 20 percent chance that you will come off the ventilator," New York Gov. Andrew Cuomo said last week. "The longer you are on the ventilator, the lower the chance that you come off."

The new research had several important caveats. It was a small study, and its authors did not compare their patients' outcomes with a control group to know for sure whether the improvements were truly due to remdesivir, or whether they would have gotten better on their own, without treatment.

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Infectious disease experts were cautious, but optimistic, in interpreting the findings.

"I would say it's an incremental and potentially positive piece of data in the journey to understand what antivirals are going to be the most helpful," said Dr. Greg Poland, an infectious disease expert and director of the Mayo Clinic's Vaccine Research Group in Rochester, Minnesota.

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Remdesivir is an antiviral therapy, thought to work by blocking the virus from replicating itself in the body. The new study did not, however, provide any information on whether the drug actually worked by reducing levels of the virus in patients' bodies.

Previous research in animals had shown the drug, developed by Gilead Sciences, might treat MERS, another type of coronavirus. It was also widely promoted as a potential treatment for Ebola, but failed to show any significant benefit.

Then came COVID-19, which has now sickened nearly a half million people in the U.S. Remdesivir was used as an experimental therapy for the first person in the U.S. diagnosed with the disease, and appeared to have helped that patient. It's been given to other very ill patients through compassionate use, meaning no other proven therapies were available.

Mild to moderate liver function abnormalities were noted as a side effect in the new remdesivir research. But it's unclear whether those problems were a result of the drug, or the disease itself.

Meanwhile, Gilead, which was involved in this latest research, has begun enrolling up to 1,000 patients for more robust clinical trials on remdesivir.

"We won't have definitive information until we have a controlled trial," said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University. Neither Schaffner nor Poland were involved with the new research.

Still, the results remain promising for the coronavirus which, so far, has no cure or proven treatment.

"If you said to me, 'Let's say you had a severe case and you had a choice to go on a remdesivir clinical trial, would you do it?'" Poland said. "My answer is yes."

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