© 2024 Maine Public | Registered 501(c)(3) EIN: 22-3171529
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations
Scroll down to see all available streams.

Drug, Pending FDA Approval, Could Help Treat Rare Form of Muscular Dystrophy

Patty Wight
/
MPBN
Patrick Denger

In April, families across the U.S. traveled to Maryland to urge a Food and Drug Administration advisory committee to support a landmark drug for Duchenne muscular dystrophy.

After a meeting that stretched more than 10 hours, the committee recommended against the drug’s approval, citing insufficient evidence of its efficacy. But the final say rests with the FDA, which one family in Maine holds out hope will approve the drug that could be the first ever to slow the progression of the disease.

For many, getting a driver’s license marks a turning point in life, a ticket to independence. For 21-year-old Patrick Denger of Biddeford, that independence was even more pivotal, because he relies on his parents to help him with basic daily tasks like getting out of bed in the morning, putting on a shirt and using the bathroom.

Patrick has Duchenne muscular dystrophy. It’s a rare genetic disorder that mostly affects boys. The average life expectancy is the mid-twenties, because Duchenne causes progressive muscle weakness.

Patrick lost the ability to walk at age 13. He can lift his arms just a few inches above his lap.

Patrick uses a motorized wheelchair to get around. But he can drive it into a specially equipped van and park it front of the steering wheel.

He uses a touch screen to switch gears and a joystick to steer. When Patrick slipped into the driver’s seat for the first time a few years ago, it shifted his outlook. He could see himself having a career, driving to and from work someday.

“It gives you a sense of purpose,” he says. “If you have that independence, you have more reason to get up everyday and do things, enjoy life.”

Patrick wants to preserve his independence. To do it, he needs to retain the muscle strength he has. And there’s a drug that could help him. It’s called eteplirsen. The FDA is considering whether to approve it.

“There is, without question, a profound unmet medical need in DMD,” says the FDA’s Dr. Billy Dunn, opening an advisory committee meeting in April on eteplirsen. “We have no approved treatments for this disease. We are highly sensitive to the urgent need of improved treatment for Duchenne.”

If approved, eteplirsen would be the first drug that offers actual treatment for Duchenne muscular dystrophy. It helps produce a protein that preserves muscle strength that those with Duchenne can’t produce on their own.

It’s not a cure, but many who spoke during the public hearing portion of the FDA meeting — including Patrick’s dad, Brian — say eteplirsen could slow the progression of the disorder.

“We wait. And watch. As function is lost, never to be regained. Each one of us asks, how much longer?” Brian says.

He has witnessed the loss of function twice. Another son, Matthew, also had Duchenne and died of heart failure a few years ago, at the age of 20. Brian wants to preserve the remaining muscle function Patrick now has.

“We want Patrick to be able to continue playing piano, to continue — he drives a van with hand controls, to use his laptop computer for communication, to continue his education,” he says. “He’s a student at the University of New England and he hopes to graduate with a degree in psychology. We want him to do all those things.”

According to the company that’s developing eteplirsen, Sarepta Therapeutics, a clinical trial shows the drug produces the missing muscle protein in Duchenne and would therefore benefit patients. But that clinical trial involved just twelve participants.

That wasn’t big enough or have enough placebo control to win the support of the FDA committee, which voted against recommending approval.

“I can understand, from their perspective, why they had trouble approving it. The study was very small,” says Dr. Thomas Reynolds, a pediatric neurologist at Maine Medical Center.

Reynolds says, though, there may be instances when the standard criteria for robust scientific studies for a new drug may be unrealistic. Why, he asks, would anybody with a progressive, ultimately terminal disease, want to take a placebo instead of a drug that could help them?

“This is not just about eteplirsen, but a larger question about how we evaluate and approve treatments for rare and progressive diseases,” he says.

Patrick is currently part of a clinical trial for a competing drug to treat Duchenne that just lost a bid for FDA approval. Brian says that drug has side effects that eteplirsen doesn’t. After years of frustration over the lack of treatment options, he sees eteplirsen as the first step toward meaningful treatment for Duchenne.

“The question becomes: if you approve this drug, and you’re not getting the benefit you anticipated, what have you gained, and what have you lost? I don’t think you’ve lost a whole lot.” he says.

The FDA is scheduled to decide whether to approve eteplirsen by May 26.