Selective Inhibitors of Dual Leucine Zipper Kinase (DLK, MAP3K12) with Activity in a Model of Alzheimer’s Disease Snahel Patel, † William J. Meilandt, ‡ Rebecca I. Erickson, ∥ Jinhua Chen, # Gauri Deshmukh, ⊥ Anthony A. Estrada, † Reina N. Fuji, ∥ Paul Gibbons, † Amy Gustafson, ∇ Seth F. Harris, § Jose Imperio, ‡ Wendy Liu, † Xingrong Liu, ⊥ Yichin Liu, ∇ Joseph P. Lyssikatos, † Changyou Ma, # Jianping Yin, § Joseph W. Lewcock,* ,‡ and Michael Siu* ,† † Department of Discovery Chemistry, ∥ Department of Safety Assessment, § Department of Structural Biology, ‡ Department of Neurosciences, ⊥ Department of Drug Metabolism and Pharmacokinetics, and ∇ Department of Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States # Department of Chemistry, WuXi AppTec Co., Ltd., 288 Fute Zhonglu, Wai Gao Qiao Free Trade Zone, Shanghai 200131, P. R. China * S Supporting Information ABSTRACT: Significant data exists to suggest that dual leucine zipper kinase (DLK, MAP3K12) is a conserved regulator of neuronal degeneration following neuronal injury and in chronic neurodegenerative disease. Consequently, there is considerable interest in the identification of DLK inhibitors with a profile compatible with development for these indications. Herein, we use structure-based drug design combined with a focus on CNS drug-like properties to generate compounds with superior kinase selectivity and metabolic stability as compared to previously disclosed DLK inhibitors. These compounds, exemplified by inhibitor 14, retain excellent CNS penetration and are well tolerated following multiple days of dosing at concentrations that exceed those required for DLK inhibition in the brain. ■ INTRODUCTION Dual leucine zipper kinase (DLK, MAP3K12) dependent activation of the JNK/c-Jun pathway in neurons is essential for induction of the neuronal stress response following insult. 1−5 Abrogation of this stress response in DLK null animals results in potent protection of neurons from degeneration in multiple neuronal injury models. 1,3,6−8 Although DLK also appears to be required for axon regeneration following peripheral nerve injury, 1,2,5,9 recent work has demonstrated that genetic deletion or pharmacological inhibition of DLK results in attenuation of synapse loss, neuronal degeneration, and functional decline in models of both Alzheimer’s Disease and Amyotrophic Lateral Sclerosis (ALS). 10 Based on these findings, the net effect of DLK inhibition would be expected to provide functional protection in the context of chronic neuronal degeneration, making DLK an attractive therapeutic target for the treatment of neurodegenerative disease. 11,12 Previously, we have disclosed two series of small molecule DLK inhibitors that effectively reduce c-Jun phosphorylation in nerve crush and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) based acute injury mouse models. 13,14 These com- pounds have served as valuable tools to enable an improved understanding of the consequences of DLK inhibition in vivo, yet challenges remain in the development of DLK inhibitors for treatment of chronic neurodegenerative disease. For these indications, a good safety profile and large therapeutic window following chronic dosing are required, which are challenging attributes to achieve with CNS-penetrant kinase inhibitors. 15 Therefore, we used structure-based design to further evolve our pyrazole scaffold (represented by compound 1) to address these challenges. Here we describe the discovery of a series of inhib- itors with an improved potency, PK, kinase selectivity, and tolerability profile with potential for prolonged administration. These compounds appear more suitable than previously reported DLK inhibitors for use in chronic neurodegenerative indications. ■ RESULTS AND DISCUSSION In prior studies, compound 1 (DLK K i = 0.042 μM, p-JNK cellular IC 50 = 0.536 μM, ClogP 3.7, tPSA 78 Å 2 , HBD 1, LipE 3.7) exhibited encouraging free drug exposure and DLK inhibition in an optic nerve crush model. 14,16,17 Although promising, further optimization was necessary to improve potency, kinase selectivity, and drug-like properties befitting a brain-penetrant therapeutic (Figure 1). Examination of the crystal structure of 1 bound to DLK 14 led us to explore alternative hydrogen bond Received: June 12, 2017 Article pubs.acs.org/jmc © XXXX American Chemical Society A DOI: 10.1021/acs.jmedchem.7b00843 J. Med. Chem. XXXX, XXX, XXX−XXX