Close Up With Mikkel Østergaard, MD, PhD, DMSc

Magnetic resonance imaging (MRI) is the most effective way to detect arthritis and other inflammatory changes in joints, but few studies have used this technology to see how medication affects disease progression in patients with psoriatic arthritis (PsA).

Now, new research shows that patients with PsA treated with Otezla (apremilast) had improvements in both clinical and MRI measures of inflammation up to week 48. Study author Mikkel Østergaard, MD, PhD, DMSc, a professor of rheumatology at the Center for Rheumatology and Spine Diseases at Rigshospitalet in Copenhagen, Denmark, spoke to Practical Dermatology about the results of the Phase 4 MOSAIC study, which he presented at the 2023 European Congress of Rheumatology (EULAR) in Milan, Italy.

MOSAIC is a multicenter, single-arm, open-label study of patients with active PsA who were treated with Otezla for 48 weeks. Patients underwent a contrast-enhanced MRI of the hand at baseline, week 24, and week 48. The study evaluated change from baseline in the composite score of hand bone marrow edema (BME), synovitis, and tenosynovitis in fingers 2 through 5, assessed by the psoriatic arthritis MRI score at week 24. Total inflammation score, comprised of BME, synovitis, tenosynovitis, and periarticular inflammation in fingers as well as structural progression, was also assessed.

Why is this topic important to study?

Mikkel Østergaard, MD, PhD, DMSc: Magnetic resonance imaging enables joint and peripheral inflammation to be visualized and offers the opportunity to better understand the disease course of psoriatic arthritis and the effects of treatment, however few studies in PsA involving MRI have been conducted to date.

Describe the research and your findings.

Dr. Østergaard: The main objective of the phase 4 MOSAIC study was to evaluate the efficacy of apremilast on inflammation, as measured by dedicated MRI of the hand. MOSAIC is the first global study to evaluate the effects of apremilast on MRI outcomes based on the PsA MRI scoring system, and whole-body MRI, which are important objective measures for the disease. PsA patients treated with apremilast had improvements in inflammation at weeks 24 and 48 and no significant structural progression was observed by MRI. Apremilast treatment led to better control of inflammation and no significant structural progression over 48 weeks in patients with moderate disease activity.

What is the next step?

Dr. Østergaard: Additional analyses of the MOSAIC study are underway, and it will be exciting to share the results in an upcoming medical congress and manuscript.

Mikkel Østergaard, MD, PhD, DMSc, is a professor of rheumatology at the Center for Rheumatology and Spine Diseases at Rigshospitalet in Copenhagen, Denmark.

Dr. Østergaard received research grants from AbbVie, Amgen Inc., BMS, Merck, Celgene, and Novartis, and speaker and/or consultancy fees from AbbVie, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Gilead, Hospira, Janssen, MEDAC, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB.