PLAN-psoriasis: protocol for a randomised controlled feasibility trial comparing patient-led 'as-needed' treatment and therapeutic drug monitoring-guided treatment to continuous treatment for adults with clear or almost clear skin on risankizumab monotherapy for psoriasis. - Ye W; Powell K; Dooley N; Thomas CM; Coker B; McAteer H; Wei JR; Tan WR; Baudry D; Dasandi T; Pizzato J; Sach TH; et al. (BMJ open, 2025)