Discovery and Optimization of Potent, Selective, and Brain-Penetrant 1-Heteroaryl-1 <i>H</i> -Indazole LRRK2 Kinase Inhibitors for the Treatment of Parkinson’s Disease
David A. Candito, Vladimir Simov, Anmol Gulati, Solomon D. Kattar, Ryan Chau, Blair T. Lapointe, Joey L. Methot, Duane E. DeMong, Thomas H. Graham, Ravi Kurukulasuriya, Mitchell H. Keylor, Ling Tong, Gregori J. Morriello, John J. Acton, Barbara Pio, Weiguo Liu, Jack D. Scott, Michael J. Ardolino, Theodore A. Martinot, Matthew L. Maddess, Xin Yan, Hakan Günaydin, R.L. Palte, Spencer E. McMinn, Lisa Nogle, Hongshi Yu, Ellen C. Minnihan, Charles A. Lesburg, Ping Liu, Jing Su, Laxminarayan G. Hegde, Lily Y. Moy, Janice D. Woodhouse, Robert Faltus, Tina Xiong, Paul J. Ciaccio, Jennifer Piesvaux, Karin M. Otte, Matthew Kennedy, David Jonathan Bennett, Erin F. DiMauro, Matthew Fell, Santhosh Neelamkavil, Harold B. Wood, Peter H. Fuller, J. Michael Ellis
Abstract
Inhibition of leucine-rich repeat kinase 2 (LRRK2) kinase activity represents a genetically supported, chemically tractable, and potentially disease-modifying mechanism to treat Parkinson’s disease. Herein, we describe the optimization of a novel series of potent, selective, central nervous system (CNS)-penetrant 1-heteroaryl-1H-indazole type I (ATP competitive) LRRK2 inhibitors. Type I ATP-competitive kinase physicochemical properties were integrated with CNS drug-like properties through a combination of structure-based drug design and parallel medicinal chemistry enabled by sp3–sp2 cross-coupling technologies. This resulted in the discovery of a unique sp3-rich spirocarbonitrile motif that imparted extraordinary potency, pharmacokinetics, and favorable CNS drug-like properties. The lead compound, 25, demonstrated exceptional on-target potency in human peripheral blood mononuclear cells, excellent off-target kinase selectivity, and good brain exposure in rat, culminating in a low projected human dose and a pre-clinical safety profile that warranted advancement toward pre-clinical candidate enabling studies.