Gene Therapy Improves ON Time for Individuals With Parkinson Disease in Phase 3 Trial

The 6-month follow-up data of a phase 2 study of a .4 x 107 TU dose of gene therapy (AXO-Lenti-PD; Axovant Gene Therapies, New York, NY) for Parkinson disease (PD) treatment showed the gene therapy improved ON time by more than 2-hours. The therapy is delivered to the putamin in a neurosurgical procedure. 

This gene therapy is investigational treatment for PD that delivers 3 genes encoding tyrosine hydroxylase, cyclohydrolase 1, and aromatic L-amino acid decarboxylase on a single lentiviral vector. These 3 enzymes are needed to synthesize dopamine from L-dopa to reduce variability and restore steady levels of dopamine in the brain. 

Data from 2 participants demonstrated a 21-point mean improvement in the unified PD rating scale (UPDRA) part 3 OFF motor function score, representing a 40% improvement from the baseline average score of 52 in these participants. The total ON time without dyskinesias and ON time with nontroublesome dyskinesias, improved an average of 2.2 hours (from a baseline mean good ON time of 10.2 hours across 4 participants.) All of the participants demonstrated improvement from baseline in diary good ON time.

OFF time decreased by an average of 2.3 hours, baseline OFF time 5.8 hours, across the 4 participants. All participants demonstrated improvement from baseline in OFF time. A 14-point mean improvement was seen in 2 evaluable participants in Cohort 2 on the UPDRS part 2 OFF score, which assesses activities of daily living, representing a 71% improvement from baseline.

The SUNRISE-PD study was a open-label, dose-escalation phase 2 trial of AXO-Lenti-PD for the treatment of PD. The 4 participants in the study had an average age of 57 years and an average duration of PD of 13 years. With the completion of this cohort, the gene therapy will be investigated for safety and tolerability of a higher volume and flow rate to increase putaminal coverage and decrease operating room time.