Benzinga | Sep 29, 2021 08:26AM EDT

PTC Therapeutics Announces Results Show Long-Lasting And Holistic Improvements In Children With AADC Deficiency Treated With PTC-AADC Gene Therapy

PTC Therapeutics, Inc. (NASDAQ:PTCT) today presented a new analysis of five-year results that shows its novel gene therapy, PTC-AADC, leads to 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.1-4 Children treated with PTC-AADC 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.1

"The transformations we are seeing in the children are remarkable, as they could not even lift their heads before treatment," said Stuart W. Peltz, Ph.D., Chief Executive Officer, PTC Therapeutics. "Treatment with PTC-AADC is restoring dopamine production, which leads to the children now being able to sit, roll over, stand and walk. They are also able to communicate, and gain both weight and strength. We believe these results show its potential as a transformational therapy for the AADC patients and their families."

The new, five-year results show 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.1-2 Across three clinical trials, improvements in motor development were recorded in all children from as early as 3 months.1 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.2

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.3 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.3

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.4

"The impact that this one-time gene therapy has had on children with AADC deficiency in these trials is truly life-changing," said investigator Paul Wuh-Liang Hwu, 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."

PTC-AADC is currently under review by the European Medicines Agency's Committee for Medicinal Products for Human Use with an opinion expected in the fourth quarter of 2021, and is an investigational new drug in the United States. A Biologics License Application is expected to be submitted to the U.S. Food and Drug Administration by the end of 2021.