Ixekizumab significantly relieves back pain, morning stiffness and disease activity in psoriatic arthritis

Atul Deodhar, in his recent study, wrote, “Ixekizumab (IXE) is a potentially therapeutic option in managing patients with psoriatic arthritis (PsA). The drug improves axial manifestations, including back pain and morning stiffness in the spine, disease activity, and fatigue (52 weeks). This study is published in Therapeutic Advances in Musculoskeletal Disease.

Among PsA patients, those with axial manifestations experience greater severity of PsA-related symptoms, which include enthesitis, dactylitis, and TJC. In this study, a team of researchers determined the efficacy of ixekizumab (IXE) up to 52 weeks in reducing axial symptoms in patients with a history of axial manifestations in a post hoc analysis of two pooled phase III clinical trials.

Patients with axial manifestations from SPIRIT-P1 and SPIRIT-P2 trials were defined as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Question 2 (Q2; back pain)] total score ⩾four and average of BASDAI Q5 + Q6 (morning stiffness) ⩾4 at baseline. IXE efficacy was evaluated at weeks 16, 24, and 52 using separate BASDAI questions, total BASDAI and modified BASDAI, Ankylosing Spondylitis Disease Activity Score (ASDAS), and 50% improvement in BASDAI (BASDAI50) response.

The key results of the study are:

• Among 313 PsA patients with axial manifestations at baseline, there were more significant improvements in back pain and morning stiffness at weeks 16 and 24 in those receiving IXE versus placebo.
• In those receiving IXE, there were greater improvements in BASDAI individual scores and total scores, mBASDAI, and ASDAS compared with placebo.
• Disease activity improved in ixekizumab-treated patients than in placebo.
• More IXE-treated patients achieved BASDAI50 at weeks 16 and 24 versus placebo.
• IXE effect was sustained at week 52.

Concluding further, IXE improves axial symptoms in patients with active PsA. It improves symptoms of back pain and morning stiffness in these patients.

The co-author of this study Gladman et al said, "Our study had the major advantage of adding two sensitivity analysis subgroups, allowing for additional data interpretation. We noted these improvements regardless of age, whether less than 45 years and regardless of inflammation level."

The study's major limitation includes a lack of a validated definition of axial and non-consideration of the HLA-B27 status or radiographs of the sacroiliac joint spine.

Further reading:

Deodhar A, Gladman D, Bolce R, Sandoval D, Park SY, Leage SL, Nash P, Poddubnyy D. The effect of ixekizumab on axial manifestations in patients with psoriatic arthritis from two phase III clinical trials: SPIRIT-P1 and SPIRIT-P2. Ther Adv Musculoskelet Dis. 2023 Aug 24;15:1759720X231189005. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10462424/