Generation of BT-Amide, a Bone-Targeted Pyk2 Inhibitor, Effective via Oral Administration, for the Prevention of Glucocorticoid-Induced Bone Loss

J Med Chem. 2024 Nov 28;67(22):20708-20720. doi: 10.1021/acs.jmedchem.4c02539. Epub 2024 Nov 14.

Abstract

Glucocorticoid-induced osteoporosis (GIOP) is the leading cause of iatrogenic osteoporosis due to the widespread clinical use of glucocorticoids (GC) as immunosuppressants. Previous research identified the proline-rich tyrosine kinase 2, Pyk2, as a critical mediator of GC-induced bone loss, and that blocking Pyk2 could protect the skeleton from adverse GC actions. However, systemic administration of current Pyk2 inhibitors causes harmful side effects, such as skin lesions. To address this, we developed bone-targeted (BT) Pyk2 inhibitors by conjugating them with bisphosphonates (BP), ensuring adherence to the bone matrix and reducing impact on noncalcified tissues. We synthesized BT-Amide by linking a derivative of TAE-226, a Pyk2 inhibitor, with alendronic acid. Oral administration (gavage) of BT-Amide prevented GC-induced bone loss in mice without causing skin lesions, or elevation of any organ toxicity markers. These findings introduce BT-Amide as the first orally effective bone-targeted Pyk2 inhibitor for preventing GC-induced bone loss while minimizing off-target effects.

MeSH terms

  • Administration, Oral
  • Amides / chemical synthesis
  • Amides / chemistry
  • Amides / pharmacology
  • Amides / therapeutic use
  • Animals
  • Bone and Bones / drug effects
  • Bone and Bones / metabolism
  • Female
  • Focal Adhesion Kinase 2* / antagonists & inhibitors
  • Focal Adhesion Kinase 2* / metabolism
  • Glucocorticoids* / adverse effects
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Osteoporosis* / chemically induced
  • Osteoporosis* / drug therapy
  • Osteoporosis* / prevention & control
  • Protein Kinase Inhibitors / administration & dosage
  • Protein Kinase Inhibitors / chemical synthesis
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use

Substances

  • Focal Adhesion Kinase 2
  • Glucocorticoids
  • Protein Kinase Inhibitors
  • Amides