Introduction Although many biologic therapies are effective for clearing skin of patients with psoriasis, some lose effectiveness over time. This phase 2 open-label extension (OLE) trial was designed to investigate the long-term safety and efficacy of risankizumab. Methods In the phase 2, double-blind, active comparator, predecessor trial (NCT02054481), patients with moderate-to-severe chronic plaque psoriasis were treated for 24 weeks with subcutaneous (SC) risankizumab or ustekinumab, followed by a 24-week follow-up without treatment administration. Patients could enroll in the OLE (NCT02203851) when they experienced loss of treatment response (