Whole-Body MRIs Reveal PsA Inflammation Improvements With Apremilast

Prof. Mikkel Østergaard, MD, PhD

Credit: Rigshospitalet

Apremilast improved inflammation in joints and entheses on hand and whole-body MRI assessments in people with psoriatic arthritis (PsA), supporting the use of whole-body MRI in PsA trials.

“Although physical examination is a crucial component of clinical evaluation, it can be subjective or inconclusive… Use of MRI in clinical trials of patients with PsA could therefore provide objective documentation of therapeutic benefit. Methods have been developed to evaluate psoriatic arthritis with MRI, such as the Psoriatic Arthritis Magnetic Resonance Imaging Scoring System (PsAMRIS) of the hand and the MRI Whole-Body Scoring System for Inflammation in Peripheral Joints and Entheses in Inflammatory Arthritis (MRI-WIPE), which enables assessment of inflammation in joints and entheses of the entire body,” lead investigator Prof Mikkel Østergaard, MD, PhD, Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, University of Copenhagen, Denmark, and colleagues wrote. “Assessing joints and entheses of the whole body is particularly relevant in patients with PsA because of the potentially widespread and diverse manifestations of the disease.”

These data are from the phase 4, multicenter, single-arm, open-label MOSAIC study (NCT03783026) conducted at 29 sites across Belgium, Canada, Denmark, Germany, Italy, Russia, Spain, Switzerland, the UK, and the USA. The study enrolled 123 adults with PsA and at least 3 swollen and 3 tender joints with hand involvement and at least 1 active enthesitis site according to the Spondyloarthritis Research Consortium of Canada enthesitis index or the Leeds enthesitis index between February 2019 and May 2022. Participants received apremilast 30 mg orally twice per day after a 5-day titration period. Concomitant stable methotrexate up to 25 mg per week was permitted. The primary endpoint was change from baseline to week 24 in a composite inflammation score of bone marrow edema, synovitis, and tenosynovitis in the hand as assessed by PsAMRIS and the dataset included patients that received at least 1 dose of apremilast.

Of the 123 patients enrolled, 122 (99%) were treated with apremilast and included in the full analysis set and safety population. Around half (n = 67; 55%) of the 122 were female, 55 and 116 (95%) were White. Most (n = 80; 66%) completed 48 weeks of treatment. The least squares mean change from baseline to week 24 in the composite inflammation score was −2·32 (95% CI, −4·73 to 0·09).

In terms of safety, the investigators found that 95 (78%) patients had at least 1 treatment-emergent adverse event and 6 (5%) had a severe treatment-emergent adverse event (AE). No serious AEs were considered related to treatment.

“To our knowledge, this is the first study evaluating PsAMRIS and MRI-WIPE outcomes in patients with psoriatic arthritis. Furthermore, to our knowledge, this is the first clinical study to evaluate the effects of apremilast on MRI outcomes. Our results show the use of dedicated MRI and whole-body MRI as objective tools to measure inflammatory changes in psoriatic arthritis and of validated MRI scoring systems as objective measures of inflammatory arthritis,” Østergaard and colleagues concluded.

MRI assessments continue to grow in importance in the diagnosis and classification of rheumatic diseases, including PsA and axial spondyloarthritis (AxSpA). HCPLive recently spoke with Philip Mease, MD, Clinical Professor, University of Washington School of Medicine and Director, Rheumatology Research, Swedish Medical Center, about research he is working on with classifying axial inflammation in people with PsA.

“We know that in psoriatic arthritis, one of the clinical domains that can be present is axial inflammation, or spine inflammation. This is an immunologic process in the spine and sacroiliac joints,” Mease told HCPLive. “This has been identified in up to 40% of patients with PsA, but we've had some difficulty in knowing how to define this. Do we do it based on clinical features? Do we base it on MRI findings or X ray findings? What about the genotype of these patients?”

REFERENCE

Østergaard M, Boesen M, Maksymowych WP, et al. Effect of apremilast on hand and whole-body MRI assessments of inflammation in patients with psoriatic arthritis (MOSAIC): a phase 4, multicentre, single-arm, open-label study. Published online October 30, 2024. doi: 10.1016/S2665-9913(24)00232-7