Eight children with Batten disease have become the first to trial a treatment that aims to save them from going blind.
Doctors at the Great Ormond Street hospital (GOSH) in London have recruited eight children with a rare type of Batten disease for a trial of a new drug. The enzyme replacement therapy will target the children’s declining eyesight. The children, four girls and four boys, are the first in the world to trial the new treatment. Aged between four and ten, all of them suffer from CLN2-type Batten disease.
Currently, there are 13 different types of Batten disease. The group of genetic disorders occur from a genetic mutation that affects the enzymes controlling the functioning of lysosomes within cells. Generally, lysosomes help break down and remove sugars, proteins, and lipids. Therefore, the genetic mutation causes a buildup of cellular waste in the body and affects brain cells. CLN2 type Batten disease is extremely rare and fatal. Symptoms usually begin at the age of 2 and include developmental delay, seizures, loss of the ability to walk or talk, and vision deterioration. By the age of 6 years, children are completely dependent on a parent or caregiver. Most children survive up to the age of 10 to 12 years.
The drug under trial is Brineura; it was first approved in 2019 for preventing neurological deterioration in children with Batten disease. The enzyme replacement therapy replaces the enzyme affected by the genetic mutation. It is administered via direct infusion into the brain and aims to slow down the disease’s progress. Although it helps prevent loss of movement and speech, it does not affect children’s eyesight since it cannot cross the blood-retinal barrier. Therefore, trial researchers will inject it into the back of the eye, under anesthesia.
Clinicians at GOSH and UCL GOS Institute of Child Health (ICH) are conducting the trial with a small amount of Brineura left over from the brain infusion. Currently, children are receiving one dose every two months, only in one eye. The researchers will continue to monitor the children for any side effects and the drug’s effectiveness. Moreover, they plan to compare the difference in sight between the two eyes after a year.
The treatment is not approved for preventing blindness; however, it is being offered on the basis of compassionate use. This allows the administration of drugs, not currently approved, in cases of life-threatening conditions where no other options are available.
Source: Great Ormond Street Hospital (GOSH)