APREMILAST REDUCES AXIAL INFLAMMATION IN PATIENTS WITH PSORIATIC ARTHRITIS AS ASSESSED BY CANDEN MRI SCORING: RESULTS FROM THE PHASE 4 MOSAIC STUDY

Background: Apremilast is an oral phosphodiesterase 4 inhibitor with a unique immunomodulatory mechanism of action and is approved for the treatment of psoriatic arthritis (PsA). Although peripheral arthritis is the most frequent clinical feature in patients with PsA, axial involvement may occur in up to 50% of patients with PsA, causing inflammatory back pain, stiffness, and changes on imaging. Here, we used whole-body magnetic resonance imaging (WB-MRI) to evaluate the efficacy of apremilast 30 mg twice daily on axial inflammation in patients with PsA. Objectives: To evaluate the efficacy of apremilast on axial inflammation in PsA. Methods: The MOSAIC study was a phase 4, single-arm, open-label trial that evaluated up to 48 weeks of apremilast treatment (with or without stable methotrexate) in patients with active PsA (per Classification Criteria for Psoriatic Arthritis [CASPAR]). Contrast-enhanced WB-MRI was performed at baseline, week 24, and week 48, and images were evaluated and adjudicated by two experienced readers who were blinded to time point and response to apremilast. In patients deemed to have PsA spondylitis by the investigator and a baseline Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Item 2 (back pain) ≥4, MRI axial inflammation was assessed by calculating the least squares mean changes from baseline to week 24 and week 48 in the Canada-Denmark (CANDEN) total spine inflammation score and subscores (assessing individual anatomical locations including posterolateral elements), the Spondyloarthritis Research Consortium of Canada (SPARCC) spine score, and the SPARCC sacroiliac joint (SIJ) inflammation score. Results: Overall, 122 patients were treated with apremilast. At baseline, the mean age was 47 years, 55% were women, mean PsA duration was 1.9 years, mean CANDEN spine score was 5.8, mean SPARCC spine score was 5.4, and mean SPARCC SIJ inflammation score was 2.7. Of the 40 patients deemed to have PsA spondylitis by the investigator and a BASDAI Item 2 ≥4, 39 patients were analyzed for axial inflammation. At weeks 24 and 48, CANDEN total spine inflammation score, vertebral body, posterior elements, corner, non-corner, and posterolateral elements inflammation subscores were significantly reduced with apremilast relative to baseline. No significant change in facet joint inflammation subscore, SPARCC spine, or SPARCC SIJ scores were observed (Figure 1). Conclusion: In patients with early PsA, apremilast reduced axial inflammation as assessed by the CANDEN MRI scoring system which provided a comprehensive and detailed anatomy-based quantification of inflammatory changes in the spine. Apremilast significantly reduced inflammation both in vertebral bodies and in posterolateral elements of the spine after 24 and 48 weeks of treatment. Figure 1. LS mean changes from baseline to weeks 24 and 48 in CANDEN spine total score and component subscores, SPARCC spine score, and SPARCC SIJ score. REFERENCES: NIL. Acknowledgements: This study was funded by Amgen Inc. Writing support was funded by Amgen Inc. and provided by Shannon Rao, PhD, employee of and stockholder in Amgen Inc. Disclosure of Interests: Mikkel Østergaard AbbVie, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Gilead, Hospira, Janssen, MEDAC, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, AbbVie, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Gilead, Hospira, Janssen, MEDAC, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, AbbVie, Amgen Inc., BMS, Merck, Celgene, and Novartis, Walter P Maksymowych CARE Arthritis Limited, AbbVie, BMS, Celgene, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, and UCB, AbbVie, Novartis, Pfizer, and UCB, Robert G Lambert Calyx, CARE Arthritis Limited, and Image Analysis Group, Mikael Boesen AbbVie, Celgene, Eli Lilly, Image Analysis Group, Novartis, Pfizer, and UCB, Image Analysis Group, AbbVie, Celgene, Eli Lilly, Image Analysis Group, Novartis, Pfizer, and UCB, AbbVie, Celgene, and Novartis, Guillermo Valenzuela AbbVie, Amgen Inc., AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Centocor, Eli Lilly, Genentech, Horizon, Janssen, Mallinckrodt, Novartis, Pfizer, Pharmacia, Radius, Regeneron, Sanofi, Takeda, and UCB, AbbVie, Alexion, Amgen Inc., Boehringer Ingelheim, Celgene, Eli Lilly, Esaote, Exagen, Genentech, Gilead, Global Health Living, Horizon, Image Analysis Group, Janssen, Merck, Novartis, Pfizer, Regeneron, Sandoz, Sanofi, and UCB, Mallinckrodt and Novartis, Michael Bubb AbbVie, Celgene, Eli Lilly, Image Analysis Group, Novartis, Pfizer, and UCB, Image Analysis Group, AbbVie, Celgene, Eli Lilly, Image Analysis Group, Novartis, Pfizer, and UCB, AbbVie, Celgene, and Novartis, Olga Kubassova Image Analysis Group, Image Analysis Group, Xenofon Baraliakos Abbvie, Amgen, BMS, Chugai, Galapagos, Gilead, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz, and UCB, Novartis and Abbvie, Carlo Selmi AbbVie, Amgen, Alfa-Sigma, Biogen, Eli-Lilly, EUSA Pharma - Recordati, Galapagos, Janssen, Novartis, Octapharma, Pfizer, Recordati Rare Disease, and SOBI, AbbVie, Amgen, Alfa-Sigma, Biogen, Eli-Lilly, EUSA Pharma - Recordati, Galapagos, Janssen, Novartis, Octapharma, Pfizer, Recordati Rare Disease, and SOBI, AbbVie, Amgen, Janssen, Novartis, and Pfizer, Stephen Colgan Amgen Inc, Amgen Inc, Yuri Klyachkin Amgen Inc., Amgen Inc., Cynthia Deignan Amgen Inc., Amgen Inc., Zhenwei Zhou Amgen Inc., Amgen Inc., Philip J. Mease AbbVie, Amgen Inc., Eli Lilly, Janssen, Novartis, Pfizer, and UCB, AbbVie, Amgen Inc., Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, Sun, UCB, Boehringer Ingelheim and GlaxoSmithKline, AbbVie, Amgen Inc., Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, Sun, and UCB, DOI: 10.1136/annrheumdis-2024-eular.2763 Keywords: Outcome measures, Targeted synthetic drugs, Magnetic Resonance Imaging Citation: , volume 83, supplement 1, year 2024, page 707Session: Psoriatic arthritis (Poster View)

Outcome measures, Targeted synthetic drugs, Magnetic Resonance Imaging