MLi-2, a Potent, Selective, and Centrally Active Compound for Exploring the Therapeutic Potential and Safety of LRRK2 Kinase Inhibition

• Published in: The Journal of pharmacology and experimental therapeutics Vol. 355; no. 3; pp. 397 - 409
• Main Authors: Fell, Matthew J, Mirescu, Christian, Basu, Kallol, Cheewatrakoolpong, Boonlert, DeMong, Duane E, Ellis, J Michael, Hyde, Lynn A, Lin, Yinghui, Markgraf, Carrie G, Mei, Hong, Miller, Michael, Poulet, Frederique M, Scott, Jack D, Smith, Michelle D, Yin, Zhizhang, Zhou, Xiaoping, Parker, Eric M, Kennedy, Matthew E, Morrow, John A
• Format: Journal Article
• Language: English
• Published: United States 01.12.2015
• Subjects: Alveolar Epithelial Cells - drug effects; Alveolar Epithelial Cells - pathology; Animals; Antiparkinson Agents - adverse effects; Antiparkinson Agents - therapeutic use; Behavior, Animal - drug effects; Binding, Competitive; Brain - metabolism; Brain Chemistry - drug effects; Cell Line; Cerebral Cortex - drug effects; Cerebral Cortex - metabolism; Dose-Response Relationship, Drug; Humans; Indazoles - pharmacology; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Lung - pathology; Male; Mice; Mice, Inbred C57BL; Mutation - genetics; Parkinson Disease - drug therapy; Parkinson Disease - pathology; Parkinson Disease - psychology; Phosphorylation; Protein Kinase Inhibitors - adverse effects; Protein Kinase Inhibitors - therapeutic use; Protein-Serine-Threonine Kinases - antagonists & inhibitors; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; Pyrimidines - pharmacology
• DOI: 10.1124/jpet.115.227587
• ISSN: 0022-3565

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic cause of familial and sporadic Parkinson's disease (PD). That the most prevalent mutation, G2019S, leads to increased kinase activity has led to a concerted effort to identify LRRK2 kinase inhibitors as a potential disease-modifying therapy for PD. An internal medicinal chemistry effort identified several potent and highly selective compounds with favorable drug-like properties. Here, we characterize the pharmacological properties of cis-2,6-dimethyl-4-(6-(5-(1-methylcyclopropoxy)-1H-indazol-3-yl)pyrimidin-4-yl)morpholine (MLi-2), a structurally novel, highly potent, and selective LRRK2 kinase inhibitor with central nervous system activity. MLi-2 exhibits exceptional potency in a purified LRRK2 kinase assay in vitro (IC50 = 0.76 nM), a cellular assay monitoring dephosphorylation of LRRK2 pSer935 LRRK2 (IC50 = 1.4 nM), and a radioligand competition binding assay (IC50 = 3.4 nM). MLi-2 has greater than 295-fold selectivity for over 300 kinases in addition to a diverse panel of receptors and ion channels. Acute oral and subchronic dosing in MLi-2 mice resulted in dose-dependent central and peripheral target inhibition over a 24-hour period as measured by dephosphorylation of pSer935 LRRK2. Treatment of MitoPark mice with MLi-2 was well tolerated over a 15-week period at brain and plasma exposures >100× the in vivo plasma IC50 for LRRK2 kinase inhibition as measured by pSer935 dephosphorylation. Morphologic changes in the lung, consistent with enlarged type II pneumocytes, were observed in MLi-2-treated MitoPark mice. These data demonstrate the suitability of MLi-2 as a compound to explore LRRK2 biology in cellular and animal models.