A 3-year-old girl who underwent a breakthrough gene therapy treatment to treat profound hearing loss can hear on her own, two years after the treatment.
Opal Sandy made history in 2023 when at 11 months old, she became the youngest patient in the world to have a gene therapy injection to her right ear, a breakthrough treatment for the deafness she was born with due to mutations of the OTOF gene, an inherited condition.
The gene therapy treatment -- a 15-minute procedure during which Opal was under general anesthesia -- delivered a working copy of the OTOF gene into Opal's right cochlea, the hollow and spiral tube in the inner ear.
During the same procedure, done in the United Kingdom, where Opal's family lives, doctors placed a cochlear implant on Opal's left ear.
Today, two years after the procedure, Opal's parents say their daughter can hear normally, even when the cochlear implant on her left ear is turned off.
Opal's mom Jo Sandy told "Good Morning America" the transformation she has seen in daughter's ability to hear is "mind blowing."
She said that prior to the procedure, neither Opal nor her older sister Nora, 6, who was born deaf due to the same inherited condition, could hear even the "highest levels" of noise.
"Both girls had no hearing whatsoever," Sandy said. "So we're talking like big, massive drums and cymbals being banged behind their heads. There was never a response, even at the very highest levels that they can test."
Opal's procedure was done as part of a clinical trial for the therapy -- known as DB-OTO gene therapy -- with patients in the U.K. as well as the United States, Spain and Germany.
Regeneron, the New York-based pharmaceutical company investigating the DB-OTO therapy, announced on Oct. 12 that 11 of 12 patients in the clinical trial, including Opal, experienced "clinically meaningful" improvements in hearing "within weeks" of the procedure, and many continue to see progress to this day.
The trial is continuing to enroll kids under age 18, according to Regeneron.
