A new analysis of 5-year results with novel gene therapy, PTC-AADC, presented at 50th Child Neurology Society Annual Meeting, has shown profound improvements in children with aromatic L-Amino acid decarboxylase ( AADC ) deficiency, a previously intractable, fatal and devastating rare disorder of the central nervous system.
Children treated with PTC-AADC have developed motor function and cognitive skills not previously seen, such as holding up their head, sitting or standing with support and communicating, and these persisted for up to 10 years.
The new, 5-year results have shown that motor function improvements were sustained, demonstrating that the treatment effect of PTC-AADC is durable, which is highly important for a single administration therapy for a chronic, fatal disease.
Across three clinical trials, improvements in motor development were recorded in all children from as early as 3 months.
Cognitive and language skills were also reported to improve significantly from baseline, as measured by Bayley-III scores, with children able to understand their caregivers and express themselves.
In addition, the rate of respiratory infection declined from an average of 2.4 episodes per year at 12 months to 0.6 episodes per year at 2 years and 0.3 episodes per year at 5 years.
Almost all treated children went from a baseline weight below the third percentile to making age-appropriate weight gains by 12 months following gene therapy treatment.
There are currently no approved disease-modifying therapies for AADC deficiency, a fatal disorder caused by a defective gene that stops the body from producing the dopamine needed to develop and function normally.
Delivering PTC-AADC gene therapy directly to the putamen, a site in the brain where dopamine is utilized, corrects this defect.
AADC deficiency is a fatal, rare genetic disorder that causes severe disability and suffering from the first months of life, affecting every aspect of life – physical, mental, and behavioral.
The suffering of children with AADC deficiency is exacerbated by episodes of distressing seizure-like oculogyric crises, which can happen daily and last for hours, causing the eyes to roll up in the head, frequent vomiting, behavioral problems, difficulty sleeping, and life-threatening complications such as respiratory infections and gastrointestinal problems. ( Xagena )
Source: PTC Therapeutics, 2021