A Closer Look At Remdesivir, An Experimental Coronavirus Drug

Biotech company Gilead Sciences announced over the weekend that it will expand access to its experimental treatment for the coronavirus — called remdesivir — after it halted emergency access.

Remdesivir has been tested against many different viruses and shown “good activity in the laboratory” against coronaviruses, says Rear Admiral Richard Childs. The antiviral agent isn’t new, but it’s never been approved for use, he says.

“It interferes with the ability of the RNA virus to reproduce itself, interfering with the total number of viral particles that can invade different organs, particularly the lung,” the assistant surgeon general and lung specialist at the National Institutes of Health says.

Childs led a team sent to Japan to screen Americans on the Diamond Princess cruise ship and bring them home. Some of the sickest patients were given remdesivir, he says.

Of the 51 Americans hospitalized throughout Japan with COVID-19, 14 were critically ill. With the average age of 75 years old, these patients had severe pneumonia and were put on ventilators or ECMO machines, which are heart lung bypass machines, in intensive care units, he says.

“Looking at those first X-rays, it just hit you that, wow, this is something different,” he says. “This is a very, very severe virus that can cause incredible morbidity and mortality.”

Seven severe cases who qualified for the treatment were given remdesivir intravenously once a day for 10 days — and all of them survived. But Childs says this doesn’t prove remdesivir works as a treatment for the coronavirus.

The goal with antiviral and other treatments is to “buy time for the immune system to kick in,” and fight the virus, he says.

“It's really impossible to say with any certainty what role this drug played in their recovery,” he says. “What we learned was that you have to be incredibly aggressive with providing supportive care that's focused on the lungs.”

If you can keep patients with severe pneumonia alive using ventilators or ECMO machines, their immune systems will eventually figure out how to eradicate the virus, he says.

In Japan, doctors would move patients with struggling lungs to more advanced hospitals that can provide medical ventilation, he says. If their lungs looked like they would die on the ventilator, the doctors would move the patient to a tertiary medical center with ECMO machines in case they needed life support.

There’s a sense of desperation for an effective COVID-19 treatment and some people are jumping to unhelpful conclusions, Childs says. Gilead scientists say the company is overwhelmed with remdesivir orders, and some people are self-treating with antimalarial drug chloroquine.

Childs warns against assuming certain treatments are effective because they worked on some people. It’s better to wait for randomized trials that show a particular drug improves the chances of survival, he says.

“If we make that assumption incorrectly, then we are giving something to a person that may not be helping them, could potentially harm them and could be harmful in the sense that it prevents them from getting the real effective therapy,” he says. “If we just base all of our treatments on anecdotal evidence, there is a real possibility that several months from now we may be treating patients incorrectly.”

Jill Ryan produced and edited this interview for broadcast with Peter O'Dowd. Allison Hagan adapted it for the web.