Improved Motor Function in Children With Aromatic L-Amino Acid Decarboxylase (AADC) Deficiency Treated With Eladocagene Exuparvovec (PTC-AADC): Interim Findings From a Phase 2 Trial (2366)

Objective: We report interim findings from a phase 2 study on gene therapy with PTC-AADC. Background: AADC deficiency is a rare genetic disorder caused by mutations in DDC, resulting in delayed motor milestones. Design/Methods: Eight children underwent bilateral intraputaminal injection of PTC-AADC (1.8 × 1011 vg for age ≥3 years and 2.4 × 1011 vg for Results: Patients received doses of 1.8 × 1011 vg (n=3; mean age, 55.0 months) or 2.4 × 1011 vg (n=5; 24.8 months). Baseline PDMS-2 and AIMS total scores were low. All patients achieved clinically meaningful gains in motor function as measured by PDMS-2, with 50% of patients achieving full head control by month 12 after treatment. Increases from baseline in PDMS-2, AIMS, and Bayley-III total scores at 1 year were statistically significant (P Conclusions: Children with AADC deficiency achieved meaningful gains in motor function 1 year after PTC-AADC. No new safety signals were observed. Disclosure: Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi Genzyme. Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi. Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Sanofi Genzyme. Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Avexis/Norvatis. Yin-Hsiu Chien has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Biogen. The institution of Yin-Hsiu Chien has received research support from Biogen. The institution of Yin-Hsiu Chien has received research support from Sanofi Genzyme. Maria Manuel Brites has nothing to disclose. Ni-Chung Lee has nothing to disclose. Sheng-Hong Tseng has nothing to disclose. Mark Pykett has received personal compensation for serving as an employee of PTC Therapeutics. Mark Pykett has received personal compensation in the range of $500,000-$999,999 for serving as an officer or member of the Board of Directors for PTC Therapeutics. Mark Pykett has received stock or an ownership interest from PTC Therapeutics. Mark Pykett has received personal compensation in the range of $10,000-$49,999 for serving as a Observer with Pharming Group. The institution of Chun-Hwei Tai has received research support from National Taiwan University Hospital.