The p-toluenesulfonic acid salt of brepocitinib exhibits good aqueous solubility (4.84 mg/mL at pH 7.64; >7 mg/mL in simulated gastric fluids). This compound also displayed high passive membrane permeability (mean PAPP = 18.8 × 10?6 cm/s as determined using Ralph Russ canine kidney cells (RRCK)).
Class: non-receptor tyrosine kinase
Treatment: immunological disorders
Other name: PF-06700841; Brepocitinib
Elimination half-life = 3.8–7.5 h
Protein binding = 39%
PF-06700841 tosylate salt has been used as an inhibitor of Janus kinase1 (JAK1) to study its therapeutic effect on the adjuvant induced arthritis (AIA) rat model. It has also been used as an inhibitor of interferon-α/β receptor alpha chain (IFNAR1) signaling adaptor tyrosine kinase (2TYK2) in mice.
PF-06700841 prevents IL-23 (interleukin 23) signaling through TYK2 (Tyrosine-protein kinase 2)/JAK1 (Janus kinase 1) inhibition.
The high oral bioavailability of brepocitinib obtained from rats (83%) is consistent with its high passive permeability and good solubility. The elimination half-life of brepocitinib ranged from 3.8 to 7.5 h after a single oral dose and from 4.9 to 10.7 h after multiple-dose administration. It was eliminated from the body by CYP450-mediated hepatic metabolism (84%) (mainly via CYP3A4) and renal clearance (16%). Oxidation of the N-methyl pyrazole (2) is the major metabolic pathway, followed by N-demethylation (3) and N-dealkylation with loss of pyrazole (4).
