Table 2.

Summary of pharmacokinetic parameters

Pharmacokinetic parameter	Details
Dose-dependent rise	Dose-dependent rise in plasma Cmax and AUC up to 200 mg, indicating proportional escalation.
Steady-state plasma	Reaches steady-state plasma concentrations in 48 hours with daily treatment.
Absorption	Oral bioavailability: ~60% Peak plasma concentration: Within 1 hour
Distribution	Volume of distribution: ~100 L (after intravenous injection) Plasma protein binding: Abrocitinib (64%), Metabolites M1 (37%) and M2 (29%) Binding: Similar amounts in red blood cells and plasma, mostly to albumin
Elimination	Cleared mainly through metabolic processes Half-lives: Abrocitinib and its active metabolites (M1 and M2) - 3–5 h
Metabolism	Major enzymes involved: CYP2C19 (~53%), CYP3A4 (~11%), CYP2C9 (~30%), CYP2B6 (~6%) Active metabolites: M1 (less active), M2 (similar activity to abrocitinib) Unbound exposure: Abrocitinib (~60%), M2 (~30%), M1 (~10%)
Excretion	<1% of a single dose eliminated as unchanged drug in urine Main metabolites (M1 and M2) eliminated in urine, act as substrates for the OAT3 transporter