Local company: Data on first RSV treatment looks promising

Respiratory virus sickens millions of children every year

WATERTOWN, Mass. — It’s a virus that was first discovered when Dwight Eisenhower occupied The White House, but 66 years later there is still no specific drug therapy for Respiratory Syncytial Virus infections -- known to most as RSV.

But Watertown-based drug maker Enanta Pharmaceuticals may be drawing closer to one.

This week, the company published clinical trial data in The New England Journal of Medicine showing its anti-RSV drug EDP-938 dramatically reduced both the amount of virus and severity of symptoms in human subjects inoculated with RSV when compared with a placebo.

“Almost immediately, from the time the drug was delivered, there was a marked differentiation in the two groups that just completely altered the course of the infection,” said Jay Luly, PhD, president and CEO of Enanta. “The viral loads came down. Symptoms came down.”

EDP-938 targets a key protein involved in viral replication, Luly said.

“It’s called the n-protein or nucleoprotein,” he explained. “By hitting that target we can actually stop the replication, the amplification of the virus.”

To have a drug like that on hand would be a “game-changer,” said Lawrence Rhein, MD, MPH, chair of the Department of Pediatrics at UMass Memorial Medical Center in Worcester and a specialist in pediatric pulmonology.

“It would be incredible,” Rhein said. “The number one cause of bronchiolitis is RSV. The number one cause of hospitalization in young children under two was RSV bronchiolitis. So if there’s a treatment for RSV bronchiolitis, it changes the game for a lot of children -- not only because of the acute issues of hospitalization, but (RSV infection) has been associated with long-term wheezing and long-term pulmonary issues.”

But for most children, the virus is an uncomfortable rite of passage -- and little more than that. And RSV infects a LOT of children.

“It’s a near universal infection,” Luly said. “Almost every child in the world gets at least one or maybe multiple RSV infections by the time they’re 2 years old.”

It can also severely affect the elderly and immunocompromised, Luly said.

“So you have a number of different patient populations that are vulnerable,” he said. “In fact, dramatically impacted by this virus and yet there are no drug treatments available.”

Usually, RSV outbreaks begin as summer winds down and peak during the colder months.

“You know, it was one of those things you could predict every single year for decades,” Rhein said.

But since the pandemic began, RSV has been all over the map. Mask-wearing and other COVID-19 precautions largely prevented the virus from rising when it should have. But that didn’t stop it from rising eventually. In Worcester County, doctors dealt with an RSV surge beginning last summer.

As mask mandates come to an end this winter, it’s not hard to predict what the effect will be from a medical standpoint.

“Some of these regular communicable diseases are coming back,” Rhein said. “RSV is still a problem.”

For now, it will continue to be a problem without a specific treatment -- as EDP-938 is set to undergo further clinical trials -- including in children, older adults and the immunocompromised.

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