Abelson Tyrosine Kinase Inhibitors in Parkinson's Disease and Lewy Body Dementia: A Systematic Review, Meta-analysis, and Meta-regression.

Background: Alpha-synucleinopathies are incurable neurodegenerative diseases. Abelson tyrosine kinase inhibitors (Abl TKIs) may be disease-modifying therapies. This systematic review, meta-analysis, and meta-regression evaluated the use of Abl TKIs in their treatment.

Methods: We searched PubMed, Embase, and Cochrane databases for trials using Abl TKIs in patients with Parkinson's disease and Lewy body dementia published until July 2023. The outcome was the change in the MDS-UPDRS-III (Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale III). DerSimonian-Laird random-effects model was used to calculate the pooled effect estimates. Leave-one-out forest plots were used for the sensitivity analysis, and meta-regression (restricted maximum likelihood) was performed.

Results: Five studies (197 patients) were included. Nilotinib 300 mg had an effect size of -1.154 (95% confidence interval [CI], -3.000 to 0.692). Nilotinib 150 mg and bosutinib 100 mg versus placebo yielded 0.82 (95% CI, -3.76 to 5.41). Sensitivity analysis showed that 1 trial changed the significance of the nilotinib 300 mg single-arm analysis (MD = -1.723; 95% CI, -2.178 to -1.268). Meta-regression revealed that lower age (EC = -0.9103, SE = 0.2286, P < 0.0001) and higher baseline MDS-UPDRS-III scores (EC = 0.1210, SE = 0.0168, P < 0.0001) could explain the inefficacy of nilotinib 300 mg.

Conclusions: Nilotinib (300 mg) proved effective postsensitivity analysis, unlike lower doses and bosutinib in Parkinson's disease/Lewy body dementia. Abl TKIs showed reduced efficacy in younger, more impaired patients, indicating the need for further testing with higher-potency drugs in patients who have diseases that are in the early stage but with a later onset.