From:  Gene therapy for Parkinson’s disease: a new frontier in neurodegenerative diseases

 Recent results of clinical studies on PD gene therapy.

Eligibility criteriaTargeted genes and vectorAdministration processSafety/Toxicity/EfficacyOutcome measuresFollow-up and monitoringClinical trials identifier and reference(s)
PD subjectsAADC, AAV2-hAADChAADC-expressing adeno-associated serotype 2 viral vectors were delivered by bilateral intra-putaminal infusionsSafe and tolerable, very few persons reported SAEs. Phase I studiesThere was a significant improvement in putaminal uptake and AADC activity, and signs of dopamine signaling restoration. There is currently a clinical hold on the phase 2 VY-AADC02 projectNCT03065192/NCT03562494 [49]
PD patients with mild to moderate, and moderate to severeAADC, LV-GCH1-TH-AADCBilateral administration into the putamenSafe and tolerable, but there were 3 SAEs: dyskinesia, severe psychosis, and an unidentified nervous system disorder. Every dosing cohort has a comparable safety profile. After four and six years, two deaths were reported; these were deemed to be unconnected to the treatmentIn all patients, an improvement in motor score was observed. Specifically, a remarkable improvement in mean UPDRS part III motor scores off medication was recorded in all patients at 6 months compared with baseline6-month follow-up by Sio Gene TherapiesNCT00627588/NCT01856439
Early PD patientsSmall molecular GBA geneOral administration of GZ/SAR402671Safe and tolerableThe phase I trial was ended since its primary and secondary objectives were not achievedNCT02906020
Idiopathic PD patientsCERE-120 (neurturin gene), AAV2-neurturinAdministered bilaterally into the substantia nigra and putamenIt was well tolerated and safe, but also caused AEsIt failed to improve the patients’ conditionsNCT00985517/NCT00400634
Advanced-stage PD patientsGAD genes, AAV-GADSurgical infusion into the subthalamic nucleusIt was safe and well-toleratedUPDRS showed significant improvements in motor functionNCT00195143 [5052]

AADC: L-amino acid decarboxylase; AAV2-hAADC: adeno-associated virus 2-human AADC; PD: Parkinson’s disease; SAEs: serious adverse effects; LV-GCH1-TH-AADC: lentiviral-GTP cyclohydrolase 1-tyrosine hydroxylase-AADC; UPDRS: Unified Parkinson’s Disease Rating Scale; GBA: glucocerebrosidase; GAD: glutamic acid decarboxylase.