title: MLi-2, a Potent, Selective, and Centrally Active Compound for Exploring the Therapeutic Potential and Safety of LRRK2 Kinase Inhibition.
abstract: 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.
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.) matthew.fell@merck.com.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Fell
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Christian
authors.initials: C
authors.lastname: Mirescu
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Kallol
authors.initials: K
authors.lastname: Basu
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Boonlert
authors.initials: B
authors.lastname: Cheewatrakoolpong
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Duane E
authors.initials: DE
authors.lastname: DeMong
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: J Michael
authors.initials: JM
authors.lastname: Ellis
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Hyde
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Carrie G
authors.initials: CG
authors.lastname: Markgraf
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Hong
authors.initials: H
authors.lastname: Mei
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Michael
authors.initials: M
authors.lastname: Miller
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Frederique M
authors.initials: FM
authors.lastname: Poulet
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Jack D
authors.initials: JD
authors.lastname: Scott
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Smith
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Zhizhang
authors.initials: Z
authors.lastname: Yin
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Eric M
authors.initials: EM
authors.lastname: Parker
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Kennedy
authors.affiliation: Neuroscience Discovery (M.J.F., C.M., M.E.K) and Discovery Chemistry (J.M.E), Merck Research Laboratories, Boston, Massachusetts; Discovery Chemistry (K.B., D.E.D., M.M., J.D.S.), Pharmacology (B.C., L.A.H., Y.L., E.M.P., M.D.S., Z.Y., X.Z.), Pathology and Cellular Toxicology (C.G.M., F.M.P), and Pharmacokinetics (H.M.), Merck Research Laboratories, Kenilworth, New Jersey; Neuroscience Discovery, Merck Research Laboratories, West Point, Pennsylvania (J.A.M.).
authors.forename: John A
authors.initials: JA
authors.lastname: Morrow
mesh_terms: D056809:Alveolar Epithelial Cells / Q000187:drug effects / Q000473:pathology; D000818:Animals; D000978:Antiparkinson Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D001522:Behavior, Animal / Q000187:drug effects; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D002460:Cell Line; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007191:Indazoles / Q000494:pharmacology*; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation / Q000235:genetics; D010300:Parkinson Disease / Q000188:drug therapy / Q000473:pathology / Q000523:psychology; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*
chemical_list: C000604693:2,6-dimethyl-4-(6-(5-(1-methylcyclopropoxy)-1H-indazol-3-yl)pyrimidin-4-yl)morpholine; D000978:Antiparkinson Agents; D007191:Indazoles; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; C495279:Lrrk2 protein, mouse; D017346:Protein Serine-Threonine Kinases