Trial Results Show Gene Therapy Causes Improvements in Children with AADC Deficiency 

A new analysis of clinical trial results shows that a novel gene therapy (PTC-AADC; PTC Therapeutics, South Plainfield, NJ) leads to profound improvements in children with aromatic L-amino acid decarboxylase (AADC) deficiency, a rare, intractable, and fatal disorder of the central nervous system.

Children treated with PTC-AADC developed motor function and cognitive skills not seen in the natural history of this condition, including holding up their head, sitting or standing with support, and communicating. These developmental gains persisted for up to 10 years in trial participants. There are currently no approved disease-modifying therapies for AADC deficiency.  

"The impact that this one-time gene therapy has had on children with AADC deficiency in these trials is truly life-changing," said Paul Wuh-Liang Hwu, MD, PhD, National Taiwan University Hospital. "We are encouraged by the strong safety profile and long-lasting effect seen with PTC-AADC, and how it has improved the lives of patients and their caregivers." 

Across 3 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 after gene therapy treatment.