Long-term follow-up of a randomized AAV2-GAD gene therapy trial for Parkinson’s disease
Martin Niethammer, … , Michael G. Kaplitt, Andrew Feigin
Martin Niethammer, … , Michael G. Kaplitt, Andrew Feigin
Published April 6, 2017
Citation Information: JCI Insight. 2017;2(7):e90133. https://doi.org/10.1172/jci.insight.90133.
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Clinical Medicine Neuroscience

Long-term follow-up of a randomized AAV2-GAD gene therapy trial for Parkinson’s disease

Abstract

BACKGROUND. We report the 12-month clinical and imaging data on the effects of bilateral delivery of the glutamic acid decarboxylase gene into the subthalamic nuclei (STN) of advanced Parkinson’s disease (PD) patients.

METHODS. 45 PD patients were enrolled in a 6-month double-blind randomized trial of bilateral AAV2-GAD delivery into the STN compared with sham surgery and were followed for 12 months in open-label fashion. Subjects were assessed with clinical outcome measures and 18F-fluorodeoxyglucose (FDG) PET imaging.

RESULTS. Improvements under the blind in Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores in the AAV2-GAD group compared with the sham group continued at 12 months [time effect: F(4,138) = 11.55, P < 0.001; group effect: F(1,35) = 5.45, P < 0.03; repeated-measures ANOVA (RMANOVA)]. Daily duration of levodopa-induced dyskinesias significantly declined at 12 months in the AAV2-GAD group (P = 0.03; post-hoc Bonferroni test), while the sham group was unchanged. Analysis of all FDG PET images over 12 months revealed significant metabolic declines (P < 0.001; statistical parametric mapping RMANOVA) in the thalamus, striatum, and prefrontal, anterior cingulate, and orbitofrontal cortices in the AAV2-GAD group compared with the sham group. Across all time points, changes in regional metabolism differed for the two groups in all areas, with significant declines only in the AAV2-GAD group (P < 0.005; post-hoc Bonferroni tests). Furthermore, baseline metabolism in the prefrontal cortex (PFC) correlated with changes in motor UPDRS scores; the higher the baseline PFC metabolism, the better the clinical outcome.

CONCLUSION. These findings show that clinical benefits after gene therapy with STN AAV2-GAD in PD patients persist at 12 months.

TRIAL REGISTRATION. ClinicalTrials.gov NCT00643890.

FUNDING. Neurologix Inc.

Authors

Martin Niethammer, Chris C. Tang, Peter A. LeWitt, Ali R. Rezai, Maureen A. Leehey, Steven G. Ojemann, Alice W. Flaherty, Emad N. Eskandar, Sandra K. Kostyk, Atom Sarkar, Mustafa S. Siddiqui, Stephen B. Tatter, Jason M. Schwalb, Kathleen L. Poston, Jaimie M. Henderson, Roger M. Kurlan, Irene H. Richard, Christine V. Sapan, David Eidelberg, Matthew J. During, Michael G. Kaplitt, Andrew Feigin

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Figure 5

Display of abnormal glucose metabolism (P < 0.001, uncorrected, by SPM t test) in two representative patients using the statistical parametric mapping single-case analysis (26).

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Display of abnormal glucose metabolism (P &lt; 0.001, uncorrected, by SP...
(Increased/decreased metabolism is indicated by red/blue.) Based on the automated image-based diagnosis for individual subjects (22), one patient was classified as having idiopathic Parkinson’s disease (IPD) with a likelihood of 99%, consistent with this subject’s clinical diagnosis, and was enrolled into the study. The other subject was classified as having multiple system atrophy (MSA) with a likelihood of 99%, despite a clinical diagnosis of IPD, and thus was excluded from the study.