Title: Ustekinumab for Resistant Psoriatic Arthritis
Abstract: To the Editor: Ustekinumab is a human monoclonal antibody that targets the p40 subunit of both interleukin 12 (IL-12) and IL-23 and inhibits their activity. IL-12 and IL-23 have a key role in the differentiation and proliferation of Th1 and Th17 cell subsets. The efficacy of ustekinumab in psoriasis has been demonstrated in randomized controlled trials and it is currently licensed for the treatment of severe psoriasis. Ustekinumab was shown to have modest efficacy in a multicenter phase II study in patients with psoriatic arthritis (PsA)1, although the American College of Rheumatology20 scores were lower than in comparable studies of tumor necrosis factor (TNF) inhibitors2. Some reports … Address correspondence to Dr. D. Wallis, Department of Rheumatology, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario M5T 2S8, Canada. E-mail: dwallis{at}uhnresearch.ca