Targeted gene therapies for two rare movement disorders show meaningful clinical improvement

October 1, 2026

SEOUL — Single-dose targeted gene therapies for two rare movement disorders demonstrated clinical efficacy and the potential for disease modification, according to separate studies released at the International Congress of Parkinson’s Disease and Movement Disorders® in Seoul, Korea. 

Researchers shared the clinical outcomes of two AAV vector gene therapies for Friedreich ataxia (FA) and aromatic L-amino acid decarboxylase deficiency (AADCd), respectively. Monogenic inherited movement disorders, like FA and AADCd, can be particularly suitable candidates for advancing viral vector gene therapies, which deliver functional genes to compensate for faulty gene expression.
 
Spagarino and colleagues’ retrospective study investigated the long-term effects of the FDA-approved gene therapy Upstaza, which delivers a functional DDC gene directly to the brain that can restore dopamine production for children with AADCd. Most of the 13 children treated with this therapy achieved new motor milestones, including head control, independent sitting, supported standing or walking, and seven developed spoken language.

“These findings suggest precision gene therapy may meaningfully alter the course of AADCd and benefit this ultra-rare infantile parkinsonism-dystonia syndrome,” said Dr. Ruey-Meei Wu, research professor at National Taiwan University and medical director of the Center for Parkinsonism and Movement Disorder at NTU Hospital in Taipei, Taiwan.

Zesiewicz and colleagues conducted an early phase 1/2 study investigating a cardiotropic therapy, LX2006. Results showed neurologic stabilization or improvement in 17 adults with FA and cardiomyopathy after a single intravenous dose of AAVrh.10hFXN (LX2006). Gains were mainly seen in upper limb coordination on the modified Friedreich Ataxia Rating Scale, with propensity-matched comparisons suggesting divergence from expected natural-history decline. 

“These findings support further evaluation of systemic gene therapy as a disease-modifying approach for FA,” Wu said.

“Together, these studies highlight gene therapy’s expanding role in movement disorders, from targeted CNS delivery in pediatric neurotransmitter disease to systemic treatment for adult multisystem ataxia. Favorable safety profiles and early functional gains strengthen support for biologically targeted, disease-modifying therapies.”

Read the full abstracts: 

• Precision Gene Therapy Results in Clinical Benefit and Developmental Gains in Aromatic L-Amino Acid Decarboxylase Deficiency (AADCd): The UK Experience 

• Intravenous AAVrh.10hFXN (LX2006) Gene Therapy in Friedreich Ataxia: Early Neurologic Assessment from Two Phase 1 and 2 Studies 

All the novel research abstracts from the International Congress are available at mdsabstracts.org. 

***

About the 2026 MDS International Congress of Parkinson’s Disease and Movement Disorders^®:
The MDS International Congress is the premier annual event to advance the clinical and scientific discipline of Movement Disorders, including Parkinson’s disease. Convening thousands of leading clinicians, scientists and other health professionals from around the globe, the International Congress will introduce more than 2,000 scientific abstracts and provide a forum for education and collaboration on latest research and treatment findings. 

About the International Parkinson and Movement Disorder Society: 
The International Parkinson and Movement Disorder Society^® (MDS), an international society of more than 12,000 clinicians, scientists, and other healthcare professionals, is dedicated to improving patient care through education and research. For more information about MDS, visit www.movementdisorders.org.