TYK2/JAK1 Inhibitor PF-06700841 in Patients with Plaque Psoriasis: Phase IIa, Randomized, Double-Blind, Placebo-Controlled Trial

Trial design: We report results from a phase IIa study of efficacy and safety of PF-06700841, an oral TYK2/Jak1 inhibitor, in patients with moderate-to-severe plaque psoriasis (NCT02969018). Methods: Patients were randomized to PF-06700841 30 mg once daily (QD), 60 mg QD, or placebo (4-week induction), followed by 10 mg QD, 30 mg QD, 100 mg once weekly, or placebo (8-week maintenance). The primary endpoint was week 12 change from baseline in PASI score. Secondary endpoints were the proportion of patients achieving 75% and 90% reduction from baseline PASI at week 12. Results: In total, 212 patients in 35 sites were treated; mean (SD) baseline PASI score was 20.8 (7.68). Decreases in PASI at week 12 were statistically significant compared with placebo in five treatment groups. The greatest change from baseline (least squares mean change-17.3 [95% confidence interval,-20.0 to-14.6]) was observed in the 30-mg QD continuous treatment group. Overall, 136 patients experienced treatment-emergent adverse events, including six serious adverse events in five patients and 13 discontinuations in treatment groups because of adverse events. No herpes zoster cases or major adverse cardiac events including thromboembolic events occurred. Conclusions: PF-06700841 was generally effective and well tolerated in patients with moderate-to-severe plaque psoriasis.