Mount Dora boy among first to receive approved gene therapy drug for eye disease

A surgical team sang “I’ll be there for you,” the theme song from “Friends,” to 9-year-old Creed Pettit as he drifted off to sleep on the operating table at University of Miami’s Bascom Palmer Eye Institute earlier this week.

Creed, who lives in Mount Dora, has a rare inherited genetic disease that affects the retina — a thin layer in the back of the eye — and causes progressive vision loss and can lead to blindness.

“He has to have light in order to see anything,” said Sarah St. Pierre-Pettit, Creed’s mom. “So on rainy days or when the sun is going down or on cloudy days or at night, he can’t see at all.”

The surgery that was about to take place was a first for the team, and their patient was among the first in the U.S. to get a gene therapy drug approved by the Food and Drug Administration for an inherited genetic disease.

Perched behind a powerful microscope, Dr. Audina Berrocal, a pediatric retina surgeon, was about to inject the drug into Creed’s right eye.

“As a physician, this is the most incredible treatment,” said Berrocal in a phone interview shortly after performing the surgery on Wednesday. “We’re basically changing the genetic makeup of a person. It’s almost what we all hoped to see in our lifetime and we’re actually seeing it. It’s truly medicine and surgery at its best.”

The procedure will be done on Creed’s left eye next week.

Creed was diagnosed with the disease, called Leber congenital amaurosis, when he was 2 1/2 years old. His parents noticed that he was missing all his milestones. And when the sun would go down, he’d cry.

Eventually, a procedure called electroretinography and subsequent genetic testing at Bascom Palmer confirmed his condition.

The family was at first told that their son wouldn’t be able to read and write. But soon it became clear that with proper lighting, he could do a lot more. His parents enrolled him at Mount Dora Christian Academy, where he’s allowed to have special bright light bulbs at his desk. And he’s getting excellent grades, according to mom.

But Leber congenital amaurosis is a progressive disease and with no treatment, Creed could one day be completely blind.

Around the same time that Creed was diagnosed, a Philadelphia-based drug company called Spark Therapeutics was working on phase 3 clinical trials for a gene therapy that targeted the mutated gene. Eager to help her son, St. Pierre-Pettit tried a couple of times to enroll him in the clinical trial, but the process proved to be too hard on him.

“But I never lost hope in that. I knew sooner or later it could be done,” St. Pierre-Pettit said.

Last December, the FDA approved Spark Therapeutics’ gene therapy drug Luxturna, a one-time injection in the eye for treatment of the specific mutation.

“That was an exciting and emotional time,” St. Pierre-Pettit said.

Bascom Palmer Eye Institute, where Creed was first diagnosed nearly seven years ago, was among the seven treatment centers in the U.S. designated by Spark Therapeutics.

“​​For someone like me who has been treating these diseases, this is a breakthrough and a game-changer,” said Dr. Byron Lam, an ophthalmologist and research scientist who specializes in gene therapy and inherited eye diseases.

“When we started working, the hope was that the treatment would be approved soon and it did and he’s 9,” said Lam, a consultant for Spark Therapeutics. “Our first patient is Creed.”

He diagnosed Creed before the treatment was available.

On Wednesday afternoon, after Creed went under anesthesia, Berrocal inserted a fine needle into his eye and delivered a liquid that carried the correct version of the mutated gene.

Within 24 hours, the DNA sequence, enveloped by a benign virus, would wiggle its way through the retina’s light receptor cells and start producing the correct version of the protein.

“Now we just have to wait and see that this all works out the way we’re hoping,” said Berrocal. If all goes as expected, Creed should start seeing a difference within a month, she said.

The therapy is not a cure and it won’t miraculously make Creed’s vision perfect. But it will help him see better in low light.

Still, that’s a big difference for St. Pierre-Pettit.

“He’ll be able to see all the toys he has. He’ll see all the books on bookshelf. He’ll see all the plates, spoons. He can find all the board games. He won’t be scared of new things like bike riding and new food. And we won’t have to plan our day based on the light. We’ve been constantly chasing the sun,” she said.

At $850,000, or $425,000 per eye, the drug is among the priciest on the market. St. Pierre-Pettit said she hasn’t heard from her insurance company yet and Spark Therapeutics has helped her with some of the payments. Fundraisers and donations have also helped, she said.

It’s unknown how long the effects of the gene therapy will last. The company is planning to conduct long-term observational studies, according to the FDA.

The company wouldn’t comment on the timing and location of patients who have been treated with Luxturna since its approval, citing patient confidentiality as the reason. According to news reports two others received the gene therapy drug around the same time, one at Children’s Hospital Los Angeles and the other at Massachusetts Eye and Ear center.

nmiller@orlandosentinel.com, 407-420-5158, @naseemmiller