Orlando toddler first in Florida to get Duchenne gene therapy

The day Jaxson DeLeon got his Duchenne Muscular Dystrophy diagnosis, his mom didn’t let herself cry.

“If you cry, that’s it. You’re not going to stop crying,” Carmen Ramirez remembers thinking two years ago, when doctors told her Jaxson had this fatal, genetic condition. Duchenne has a median life expectancy of 41, according to a 2021 review.

In the last few weeks, alone in her office, Ramirez has cried without reservation.

“But it’s not because I’m upset,” she said. “I’m really that grateful.”

After decades of research, gene therapy has been approved for Duchenne Muscular Dystrophy, a degenerative muscle disease diagnosed each year in about 1 in 3,500 newborns, almost all boys. Jaxson, 4, is the first child in Florida outside of a clinical trial to receive the treatment. It was given in mid-September at Nemours Children’s Hospital in Orlando, which hosts one of eight Florida muscular dystrophy care centers that have been certified and approved by the Muscular Dystrophy Association.

Developed by Sarepta Therapeutics, Elevidys is administered by injecting a patient with a virus that treats the underlying genetic cause of Duchenne. The one-time infusion is thought to be the only approved therapy to significantly slow or even halt the progression of the uncurable disease.

“This has been a long time coming. This drug has been in the works for over 30 years now,” said the Nemours Children’s Hospital doctor who treated Jaxson, pediatric neurologist Dr. Omer Abdul Hamid.

Though the drug has potential side effects and data is limited, families are clamoring for a chance to fight the disease’s deadly outcome.

“I would do anything for my child. This will give him a chance,” Ramirez said.

LIMITED DATA, LIMITLESS INTEREST

The Food and Drug Administration gave Elevidys the green light in June under its Accelerated Approval Program, which allows drugs for serious conditions to be approved with less data than is normally required.

The approval was somewhat controversial. Data suggests the drug worked on 4- and 5-year-olds who were still able to walk, but there wasn’t strong evidence that it worked well in other age groups. The FDA’s advisory committee ultimately voted 8-6 in May to approve Elevidys, conditional on the success of a pending clinical trial. The drug is currently available only for certain 4- and 5-year-old patients.

The clinical trial will have data available by the end of the year, according to Sarepta spokesperson Sierra Smith. The FDA will likely broaden Elevidys’ age restrictions if the study succeeds. If data calls the drug into question, however, it could be taken off the market.

Hamid expressed his confidence in the drug, attributing the mixed results to the study’s small size.