Introduction: Ixekizumab (IXE) is a high‐affinity monoclonal antibody that selectively targets interleukin‐17A. This study presented integrated efficacy and safety data at Week 24 from two phase 3 trials of IXE for the treatment of psoriatic arthritis (PsA).

Methods: Patients (bDMARD‐naïve) with active PsA (SPIRIT‐P1) and with prior lack of efficacy or intolerance to TNF‐inhibitor(s) (SPIRIT‐P2) were randomized to placebo (PBO, N = 224), 80 mg IXE every 4 weeks (IXEQ4W, N = 229) or every 2 weeks (IXEQ2W, N = 226), after a 160 mg starting dose. At Week 16, PBO‐treated inadequate responders were re‐randomized to IXE and received rescue therapy. Continuous data were analyzed using mixed‐effects model for repeated measures; categorical data, using a logistic regression model with missing values imputed by non‐responder imputation. Safety data was analyzed using Fisher's exact test.

Results: At Week 24, significantly more patients treated with either dose of IXE (p<.001) compared to PBO achieved the primary endpoint of ACR 20, as well as ACR 50 and ACR 70, and had a greater change from baseline (p<.001) in HAQ‐DI score. Significantly greater rates of resolution in enthesitis (LEI) and dactylitis (LDI‐B) were seen in IXE‐treated patients compared to PBO. Greater skin clearance (via PASI improvement) was significantly higher for IXE‐treated patients (p<.001).

Treatment‐emergent adverse events (AEs) were more common in the IXE groups compared to the PBO group (p<.05). AEs that were more common in one or both IXE group(s) compared to PBO included injection site reactions, serious infections, oral candida infections, and non‐anaphylactic hypersensitivity reactions.

Conclusions: Patients treated with either dose regimen of IXE achieved significantly greater improvements in arthritis, physical function, and skin conditions compared to PBO at Week 24. Safety was generally consistent with published data from IXE psoriasis and PsA trials.