Magnetic resonance imaging characteristics in patients with psoriatic arthritis and axial manifestations from the MAXIMISE cohort

OBJECTIVE

The current analysis of the MAXIMISE trial was conducted to investigate the presence of post-inflammatory and degenerative spinal changes and inflammatory changes in spinal processes identified in baseline MRIs and their potential for predicting differential treatment effects in a cohort of PsA patients with axial manifestations.

METHODS

Baseline spinal MRIs from the MAXIMISE trial were re-read to identify additional inflammatory (spinal process), post-inflammatory, and degenerative changes, and investigate the differential treatment effect of these imaging features using logistic regression modelling.

RESULTS

In addition to bone marrow oedema assessed at primary analysis, spinal process inflammation and post-inflammatory changes evaluated by FAt Spondyloarthritis Spine Score were documented in 11.1% and 20.2% patients, respectively. At least one type of degenerative change was noted in 64% patients, with Pfirrmann grade ≥3 (51.1%) being the most common. Combining primary and re-read MRI findings, 67.1% of patients presented with inflammatory or post-inflammatory changes while 21.2% had degenerative changes alone. Although not statistically significant, post-inflammatory changes were associated with a trend for better efficacy outcomes in terms of ASAS20, ASAS40 and BASDAI50 responses; a trend for worse outcomes was observed in the presence of degenerative changes.

CONCLUSION

The current analysis revealed the occurrence of additional inflammatory and post-inflammatory changes suggestive of axial PsA (axPsA) and a trend for better clinical outcomes for patients treated with secukinumab. These results elucidate the imaging characteristics and improve our current understanding of axPsA thereby supporting the interpretation of future trials.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02721966.

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

Background

Psoriatic arthritis (PsA) is a chronic inflammatory condition predominantly affecting the peripheral joints. However, some patients with PsA can experience axial involvement which is manifested with back pain and associated with increased burden of illness.

Objectives

The aim of this post hoc analysis was to determine the efficacy of ixekizumab (IXE) up to 52 weeks in reducing axial symptoms in PsA patients, presenting with axial manifestations.

Design

This was a post hoc analysis of two pooled phase III clinical trials.

Methods

Patients with axial manifestations, from two placebo-controlled, randomized, double-blind, phase III trials (SPIRIT-P1 and SPIRIT-P2), were defined as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Question 2 (Q2; back pain)] total score ⩾4 and average of BASDAI Q5 + Q6 (morning stiffness) ⩾4 at baseline. For this post hoc analysis, the efficacy of IXE was evaluated at weeks 16, 24, and 52 using separate BASDAI questions (including back pain and morning stiffness), total BASDAI and modified BASDAI (mBASDAI; without Q3), Ankylosing Spondylitis Disease Activity Score (ASDAS), and 50% improvement in BASDAI (BASDAI50) response. Treatment comparisons were performed using logistic regression and analysis of covariance model for categorical and continuous end points, respectively.

Results

In the post hoc analysis among PsA patients with axial manifestations at baseline (N = 313), improvements in back pain and morning stiffness at weeks 16 and 24 were significantly greater in patients receiving IXE versus placebo (both p < 0.001). Improvements in BASDAI individual scores and total scores, mBASDAI, and ASDAS were significantly greater in patients receiving IXE compared with placebo. Similarly, significantly more IXE-treated patients achieved BASDAI50 at weeks 16 and 24 versus placebo. The effect of IXE was sustained at week 52. Similar effects were observed in sensitivity analyses subgroups.

Conclusion

IXE is effective in improving axial symptoms in patients with active PsA presenting with axial manifestations.