Evaluation of: Kavanaugh A, Ritchlin C, Rahman P et al.; on behalf of the PSUMMIT-1 and -2 Study Groups. Ustekinumab, an anti-IL-12/23 p40 monoclonal antibody, inhibits radiographic progression in patients with active psoriatic arthritis: results of an integrated analysis of radiographic data from the Phase 3, multicentre, randomised, double-blind, placebo-controlled PSUMMIT-1 and PSUMMIT-2 trials. Ann. Rheum. Dis. 73(6), 1000-1006 (2014). The IL-23/IL-17 axis plays a major role in the immunopathogenesis of psoriatic arthritis (PsA), inducing the production of proinflammatory cytokines (e.g., IL-1, TNF-α, IL-6 and IL8), osteoclastogenesis and cartilage degradation. This pathway represents a novel target in the treatment of PsA. Ustekinumab is a human monoclonal antibody that prevents the human IL-12/IL-23 p40 subunit from binding to the IL12Rβ1 receptor chain. The current paper sustains that clinical efficacy of ustekinumab is associated with inhibition of radiological progression in active PsA.