Adults aged 18-75 years old with stable moderate to severe plaque psoriasis for at least 6 months, may qualify to participate. Individuals must have psoriatic involvement of 10% or more body surface area. Previous failure, inadequate response, intolerance, or contraindication to at least 1 conventional anti-psoriatic systemic therapy is required. There must also be no known history of latent or active tuberculosis (TB); testing will occur at screening.
Participants will be part of one of two groups: the continued-use group (receiving ustekinumab) OR the switching group (receiving investigational medication (active study drug) and ustekinumab), via subcutaneous injection. Study medication and study-related assessments will be provided at no cost. Reimbursement for study-related expenses will also be provided.
Study participation will last about 68 weeks and involve about 14 visits to the study centre.