The Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of a TYK2/JAK1 Inhibitor (PF-06700841) in Healthy Subjects and Patients With Plaque Psoriasis

The safety, tolerability, pharmacokinetics, and pharmacodynamics of PF-06700841 were assessed in a randomized, double-blind, placebo-controlled, single- and multiple-dose escalation, parallel-group study in healthy subjects and patients with plaque psoriasis. The single ascending dose (1, 3, 10, 30, 100, or 200mg) and multiple ascending dose (MAD; PF-06700841; up to 175mg once daily or 50mg twice daily for 10 days) periods included 54 healthy participants. In addition, 30 patients with psoriasis received PF-06700841 30or 100mg or placebo once daily for 28 days. Single PF-06700841 doses were rapidly absorbed, with peak plasma concentrations 1 hour, proportional exposure up to 100mg, and mean half-life 3.8-7.5hours. On day 10 of MAD, plasma concentrations peaked at 1.5hours postdose (10-175mg once daily). Elimination half-life was 4.9-10.7hours; steady state was reached by day 8. In psoriasis patients on day 28, peak plasma concentrations occurred at 1-2hours. Biomarkers IP-10 and high-sensitivity C-reactive protein were reduced and returned to near baseline levels after dosing. Maximal mean percent change from baseline in the Psoriasis Area and Severity Index scores for PF-06700841 30mg once daily and 100mg once daily were -67.92% and -96.31%, respectively, in week 4. All adverse events were mild/moderate. PF-06700841 was safe and well tolerated up to 200mg once daily in healthy subjects and 100mg once daily in patients with psoriasis, suggesting potential therapeutic utility in plaque psoriasis and other inflammatory diseases.