The effect of ixekizumab on axial manifestations in patients with psoriatic arthritis from two phase III clinical trials: SPIRIT-P1 and SPIRIT-P2.

Ixekizumab improves symptoms of back pain and morning stiffness in patients with psoriatic arthritis Background: Psoriatic arthritis is a chronic, immune-mediated condition with heterogeneous manifestations including peripheral arthritis, axial arthritis, enthesitis, dactylitis, and skin and nail psoriasis. Some patients with psoriatic arthritis also experience symptoms relating to the spine and sacroiliac joint. These symptoms are referred to as axial manifestations of the psoriatic arthritis. Ixekizumab is a monoclonal antibody that targets IL-17A with high affinity. IL-17A has been implicated in the pathogenesis of PsA. Aim: The aim is to investigate the effects of ixekizumab in controlling symptoms suggestive of axial involvement in patients with active psoriatic arthritis. Methods: This post hoc analysis included patients with psoriatic arthritis from two phase III clinical trials. Only patients with psoriatic arthritis who had back pain and morning stiffness at baseline were included. In the second analysis, we assessed the effect of ixekizumab in a subset of patients with psoriatic arthritis with back pain who were aged less than 45 years. A third analysis included a subset of patients with increased CRP. Results: Our results show that patients with psoriatic arthritis and back pain suggestive of axial involvement experience a greater disease burden than patients without back pain. This post hoc analysis showed that ixekizumab was significantly better compared with placebo in improving inflammatory back pain, morning stiffness, and disease activity at weeks 16 and 24. Disease activity was also significantly improved in ixekizumab-treated patients compared with placebo. Conclusion: Axial manifestations in patients with psoriatic arthritis were significantly improved following ixekizumab treatment. These improvements were noted regardless of whether the patients were less than 45 years and regardless of the level of inflammation.