• Blind Boy Sees After Gene Therapy

    9-year-old patient Creed Pettit gets an eye exam after a gene therapy procedure.
    Within a month after gene therapy, Creed Pettit was able to see details of the world he'd never seen before.
    Photo credit: University of Miami

    Written By: Susanne Medeiros
    May. 14, 2018

    Creed Pettit has been slowly going blind since the day he was born. Creed has a rare genetic condition called Leber congenital amaurosis (LCA) and it makes it impossible for him to see except in bright light. As an infant, sunset would bring on fits of colic that were soothed only by the glow of street lights or the brightly-lit Publix grocery store. As he grew older, Creed managed to find his way with lamps and high-powered flashlights and he learned to read with the help of special lighting. By age 9, he carried a flashlight everywhere, including his school lunchbox, so he could see his food. Even as he found ways to work around his failing vision, time was running out. Eventually, there would be no light bright enough to help him see. Creed would be in the dark.

    But his parents had hope because they had taken Creed to Bascom Palmer Eye Institute in Miami, Fla., where he was evaluated by neuro-ophthalmologist, Byron L. Lam, MD. Though Dr. Lam had no treatment to offer when he diagnosed Creed in 2011, he did tell them that a clinical trial for a promising new gene therapy was underway at the University of Iowa. This experimental treatment would be his best shot at preserving the vision he had left. It may even improve his vision.

    Six years later, on Dec. 19, 2017, 9-year-old Creed and his family got the news they had been waiting for since he was a toddler: The FDA had approved the first gene therapy to treat an inherited disease. Called Luxturna, it's a one-time treatment for LCA that uses a harmless virus to deliver healthy copies of the gene to the retina. This time, when they returned home from Bascom Palmer, they had more than hope. They had a date for surgery: March 21.

    "Look, the dot on the i on the Cheerios box is actually a Cheerio!" – Creed Pettit

    Creed is the youngest person in the US to receive the new gene therapy. His recovery has been immediate and miraculous. His mom, Sarah Pettit, could tell his vision had improved the day after surgery. Within a month, he ditched the flashlights and lamps. He can now sit outside in the early-evening light, reading his favorite book, Diary of a Wimpy Kid, not on an iPad, but the actual paperback book. Each day brings new questions and new observations:

    "Look," he commented on a recent trip to the grocery story, "the dot on the i on the Cheerios box is actually a Cheerio!"

    "It’s a simple thing, but it's mind-blowing," Pettit said. Legally blind before surgery, Creed can now see 20/30 with glasses in his better-seeing right eye. His left eye, always his worse-seeing eye, is slowly improving.

    Even the ophthalmologists were unsure how much improvement Creed could expect from this recently approved gene therapy. Audina M. Berrocal, MD, is the pediatric retinal surgeon at Bascom Palmer who delivered the healthy genes to Creed’s eyes.

    "Usually patients lose vision," Dr. Berrocal said. "We've given vision back. It's amazing. To be able to do this for kids who, before, we've had absolutely nothing to offer in terms of treatment, it's just incredible," Dr. Berrocal said.

    Long Road to Treatment

    Dr. Audina Berrocal in the operating room performing a gene therapy procedure on 9-year-old patient Creed Pettit.
    Audina M. Berrocal, MD, is a pediatric retinal surgeon.

    Pettit knew there was something wrong with her son almost from the moment he was born. They just didn't know what it was. When a physician examined Creed under the fluorescent lights of an exam room, his eyes seemed fine. His visual acuity was 20/50 in one eye and 20/40 in the other. When a penlight was shined in his eyes, he'd reach for it.

    Even at a year old, Creed wouldn't look at people's faces, or at his food when Pettit tried to feed him. She took him from specialist to specialist, looking for an answer. He was eventually diagnosed with autism. She accepted the diagnosis, but she still knew something was wrong with his eyes. He walked with his hands outstretched in front of him, as he tripped over the dog and ran into chairs. Eventually, a therapist suggested she take him to Bascom Palmer for a neurological workup. Creed was now 3 and half.

    It was a shock when Dr. Lam told her Creed was going blind and that there was no cure. But Pettit refused to give up hope. She and Creed flew to Iowa, intent on getting in the clinical trial. He would have to clear two critical hurdles before he would be eligible. First, he had to undergo genetic testing to be sure his disease was caused by a specific genetic mutation. LCA, which affects about 1 in 80,000 individuals, can be caused by one or more of 19 different genes. Creed was in luck, he has the target gene.

    Despite 30 years of research, only a small number of gene therapy trials have advanced as far as the trial Creed was hoping to enter.

    Next, he would have to negotiate a maze while wearing sticky patches over his eyes. The patches terrified 3-year-old Creed. He couldn't do it. Undeterred, they went back to Florida, recreated the maze at home and practiced constantly. They returned to Iowa two years later to try again. It was still too much for Creed. They would have to wait until the FDA approved the drug – if it got approval at all.

    Despite 30 years of research, only a small number of gene therapy trials have advanced as far as the trial Creed was hoping to enter. For years, the concept of gene therapy – replacing or adding a gene to correct a disease-causing gene – was bogged down in disappointments and disasters. Today, the field is moving rapidly, as hundreds of clinical trials testing gene therapies are ongoing or recruiting.

    Hour-Long Procedure Restores Sight

    Creed Pettit's mother realized his vision had improved when he started noticing flowers.
    Creed's mother realized his vision had improved when he began to notice flowers.

    Was Pettit concerned the new treatment could harm her child? Yes, but she trusted Drs. Berrocal and Lam. They had faith in this treatment. As Creed went under anesthesia, the doctors asked about his favorite song. A big fan of the sitcom Friends, he started singing the theme song, "I'll Be There for You." The entire surgical team sang along with him.

    During the hour-long procedure, Dr. Berrocal injects the virus, suspended in a few drops of liquid, into a small space underneath the retina. She uses a high-powered imaging device, called optical coherence tomography, to help guide a needle the width of a human hair to the right space. Billions of modified viruses were injected into Creed's eye. About a week later, the second eye was treated. This time, the surgical team was ready. The Friends theme song was cued up to play over the speakers.

    Pettit could tell his vision was improving as early as a day or two after surgery. Creed was more at ease. He wasn't running into things and he complained that the lamps were too bright. Creed is both excited and a bit overwhelmed by how his life has changed. He peppers his mother with questions about all the things he can now see, looking at her face as he asks. He explores more outdoors, going for walks and pulling up flowers he never saw before and breathing them in.

    "Usually patients lose vision. We've given vision back. It's amazing." – Audina M. Berrocal, MD

    Dr. Berrocal follows his progress every couple of weeks right now. "We're probably going to follow this kid until the day I retire," Dr. Berrocal laughed. "I’m sure he's going to be at my retirement party."

    It is unclear how long the treatment will last, but so far, most patients who were treated during the clinical trials have maintained their vision for two years. It has been two months since Creed was treated and he hasn't had a flashlight in his lunchbox since.