The Discovery of 7-Isopropoxy-2-(1-methyl-2-oxabicyclo[2.1.1]hexan-4-yl)-<i>N</i>-(6-methylpyrazolo[1,5-<i>a</i>]pyrimidin-3-yl)imidazo[1,2-<i>a</i>]pyrimidine-6-carboxamide (BIO-7488), a Potent, Selective, and CNS-Penetrant IRAK4 Inhibitor for the Treatment of Ischemic Stroke
Ryan Evans, Philippe N. Bolduc, Magnus Pfaffenbach, Fang Gao, Tricia L. May‐Dracka, Terry Fang, Brian T. Hopkins, Jayanth V. Chodaparambil, Kate L. Henry, Pei Li, Claire M. Metrick, Ashley N. Nelson, Patrick Trapa, Ankur Thomas, Linda C. Burkly, Emily A. Peterson
Abstract
Interleukin receptor-associated kinase 4 (IRAK4) is a key node of signaling within the innate immune system that regulates the production of inflammatory cytokines and chemokines. The presence of d amage- a ssociated m olecular patterns (DAMPs) after tissue damage such as stroke or traumatic brain injury (TBI) initiates signaling through the IRAK4 pathway that can lead to a feed-forward inflammatory loop that can ultimately hinder patient recovery. Herein, we describe the first potent, selective, and CNS-penetrant IRAK4 inhibitors for the treatment of neuroinflammation. Lead compounds from the series were evaluated in CNS PK/PD models of inflammation, as well as a mouse model of ischemic stroke. The SAR optimization detailed within culminates in the discovery of BIO-7488, a highly selective and potent IRAK4 inhibitor that is CNS penetrant and has excellent ADME properties.