Remdesivir
A vial of the drug Remdesivir. Image Credit: AFP

Gilead Sciences Inc.'s remdesivir, the first medicine cleared for the treatment of COVID-19, mainly benefited healthier patients who weren't dependent on ventilators or heart-lung bypass machines, according to published results of the study used to get the medicine on the market.

The drug helped patients infected with the novel coronavirus heal faster, allowing them to return home after about 11 days, compared to 15 days for those who were treated with a placebo, according to the report in the New England Journal of Medicine. There were also signs the medicine increased their survival rate - 7.1% on patients on remdesivir and 11.9% on a placebo died within two weeks. Still, the difference wasn't statistically significant, meaning it could have stemmed from chance.

Some outside experts welcomed the findings, saying the results showed patients on remdesivir cut their recovery time by 27%.

Some investors lamented the lack of information that was initially available. The first look at the findings came when Anthony Fauci, the head of the National Institute on Allergy and Infectious Diseases, gave an overview of the findings during an event in the Oval Office with President Donald Trump last month.

The researchers, led by scientists from the National Institutes of Allergy and Infectious Diseases, analyzed initial results before all the data was available. The review led US public health officials to disclose the preliminary findings and seek emergency clearance of the medicine, which was granted by the Food and Drug Administration on May 1. While a fuller analysis is still underway, the researchers said it's already clear that antiviral drugs like remdesivir alone won't control the outbreak.

"Given high mortality despite the use of remdesivir, it is clear that treatment with an antiviral drug alone is not likely to be sufficient," the researchers concluded. "Future strategies should evaluate antiviral agents in combination with other therapeutic approaches or combinations of antiviral agents to continue to improve patient outcomes in Covid-19."

The publication also allowed greater insight into which patients seemed to respond best to treatment. The only group to do significantly better on remdesivir were those who were sick enough to need supplemental oxygen, but who weren't yet on a ventilator or a heart-lung bypass machine. While the lack of benefit might have stemmed from the limited number of patients in those groups, there were few initial signs that the drug was helping the sickest patients.

Those results could be critical because remdesivir is administered intravenously, meaning it is only given in the hospital. And many people who showed signs and symptoms of Covid-19 are currently told to stay home as long as they can. It's possible some patients who could benefit from the medicine may miss the window, if those results hold up.

"Our findings highlight the need to identify Covid-19 cases and start antiviral treatment before the pulmonary disease progresses to require mechanical ventilation," the researchers concluded.

Gilead said the publication supports the use of remdesivir in the patients studied and noted that the largest benefit was seen in those who didn't need mechanical ventilation. Another study looking at the same group of patients should be published shortly showing whether they get just as much benefit from a five day infusion as the current 10-day dose.