Stereochemical Differences in Fluorocyclopropyl Amides Enable Tuning of Btk Inhibition and Off-Target Activity
journal contributionposted on 20.07.2020, 13:33 by James J. Crawford, Wendy Lee, Adam R. Johnson, Kelly J. Delatorre, Jacob Chen, Charles Eigenbrot, Julia Heidmann, Satoko Kakiuchi-Kiyota, Arna Katewa, James R. Kiefer, Lichuan Liu, Joseph W. Lubach, Dinah Misner, Hans Purkey, Karin Reif, Jennifer Vogt, Harvey Wong, Christine Yu, Wendy B. Young
Bruton’s tyrosine kinase (Btk) is thought to play a pathogenic role in chronic immune diseases such as rheumatoid arthritis and lupus. While covalent, irreversible Btk inhibitors are approved for treatment of hematologic malignancies, they are not approved for autoimmune indications. In efforts to develop additional series of reversible Btk inhibitors for chronic immune diseases, we sought to differentiate from our clinical stage inhibitor fenebrutinib using cyclopropyl amide isosteres of the 2-aminopyridyl group to occupy the flat, lipophilic H2 pocket. While drug-like properties were retainedand in some cases improveda safety liability in the form of hERG inhibition was observed. When a fluorocyclopropyl amide was incorporated, Btk and off-target activity was found to be stereodependent and a lead compound was identified in the form of the (R,R)- stereoisomer.