Healthcare (Commonwealth Union) – Clinicians and researchers at UCL and Great Ormond Street Hospital (GOSH) have trialed a new treatment that could prevent blindness in children affected by CLN2-type Batten disease.
Published in Eye, the study demonstrated that this treatment is both safe and effective in minimizing severe vision loss, particularly when administered at an early stage.
Researchers of the study pointed out that CLN2 disease is a rare genetic disorder that affects between 30 and 50 children in the UK. It results from a mutation in a gene that produces an essential enzyme for the nervous system.
The disease typically begins with seizures, followed by a gradual loss of motor skills, speech, and vision, as well as progressive dementia. Without treatment, children with CLN2 disease have a life expectancy of around 10 to 12 years.
Since 2019, an enzyme replacement therapy called Brineura has been provided under a managed access agreement to slow neurological decline in children with CLN2 disease. However, this agreement is set to end in May 2025, making it essential to investigate the therapy’s benefits and functionality.
Administered directly into the brain via regular infusions, Brineura has been shown to restore enzyme function and slow the progression of disabilities associated with the disease.
Despite this, Brineura does not prevent vision loss in affected children, as the enzyme cannot cross the blood-retina barrier to reach the nerves in the eye, leading to eventual blindness.
In an attempt to address this, researchers at the UCL Great Ormond Street Institute of Child Health and GOSH have begun using leftover Brineura from the brain infusion to treat the eye.
This study consisted of 8 children who were already taking the Brineura treatment and experiencing advanced retinal damage. On the same day as their routine infusion treatment, they were also given the eye treatment under general anesthesia.
Most of the participants had already lost significant vision, so noticeable improvement was limited. However, younger children with less severe sight loss retained more vision in their treated eye compared to their untreated eye.
The lead researcher, Professor Paul Gissen of the UCL Great Ormond Street Institute of Child Health and GOSH says “This work is a real team approach. Our Batten’s patients are generally looked after by the metabolic team at GOSH and there has been a sad history of these children going blind.
“When Brineura was developed for the brain infusion, it was a great step forward. I supported the managed access agreement but we were still seeing these children lose their sight.
“By working with colleagues in ophthalmology, we proposed ideas, and developed a programme with Rob Henderson that we could deliver with his team at GOSH.”
The program was conducted with the pharmaceutical company’s approval, allowing the treatment itself to be provided at no additional cost. The expenses for clinical time and procedures under general anesthesia were covered by the Batten’s Disease Family Association (BDFA) and the CLN2 community, who collectively raised more than £200,000.
In 2019, Grace’s family became concerned as she began slurring her speech and frequently stumbling. At just four years old, Grace had a particularly challenging day at the zoo, where she fell around 50 times and ended up in the emergency department.
Following an urgent MRI, Grace was sadly diagnosed with CLN Type 2 Batten’s disease.
A few months after her diagnosis, Grace began receiving Brineura, which allowed her to regain her ability to walk. Since then, she has also improved her speech and can now communicate in short sentences.
Rare diseases often get less attention due to funding issues, however it does not take away the gravity of the illness for those effected hence progress is always a welcome development.
