In Vitro: Fenebrutinib (GDC-0853) inhibits CD69 expression on CD19+ B cells in human whole blood with an IC50 of 8.4±5.6 nM. Fenebrutinib inhibits CD63 expression on basophils with an IC50 of 30.7±4.1 nM. Fenebrutinib suppresses anti-IgM induced Btk Y223 autophosphorylation in human whole blood (IC50=11 nM).
In Vivo: Fenebrutinib (GDC-0853) dose-dependently reduces ankle thickness following once (0.06, 0.25, 1, 4, and 16 mg/kg QD; orally) or twice (0.125, 0.5, and 2 mg/kg BID; orally) daily in female Lewis rats with developing collagen-induced arthritis. Fenebrutinib (0.2 mg/kg IV and 1.0 mg/kg PO; for rats) and (0.2 mg/kg IV and 0.5 mg/kg PO for dogs) demonstrates the half-lives (t1/2s) of 2.2 and 3.8 h In rats, and dogs, respectively.