TYK2 and nail disorder: In the Phase 3 open-label POETYK PSO-4 trial, deucravacitinib, an oral selective TYK2 inhibitor, demonstrated rapid and sustained PASI improvement through 52 weeks in Japanese patients with moderate-to-severe plaque psoriasis, including scalp and nail disease, with a favorable safety profile, representing an effective non-biologic targeted therapy option [49].