OP0093 Effectiveness of Combination csDMARD Therapy in Psoriatic Arthritis Using Data from the MONITOR-PsA Cohort

Background: Current guidelines in psoriatic arthritis (PsA) recommend that after the failure of a first conventional synthetic disease-modifying anti-rheumatic drug (csDMARD), specifically methotrexate, sulfasalazine or leflunomide, a biologic DMARD (bDMARD) should be introduced. However, in many countries including the United Kingdom or Canada, funding agencies often require the addition of a second csDMARD, despite limited evidence supporting this approach. Objectives: Using data from the Multicentre Observational Initiative in Treat-to-Target Outcomes in Psoriatic Arthritis (MONITOR-PsA) cohort, we aimed to assess the effectiveness and feasibility of sequential and combination csDMARD therapy. Methods: The MONITOR-PsA cohort includes patients aged 18 years or older recruited from secondary care rheumatology departments in the UK with a clinical diagnosis of PsA meeting the Classification of Psoriatic Arthritis (CASPAR) criteria. Subjects had not previously been treated with DMARDs for articular disease and were managed using a treat to target strategy. For this study, patients who were prescribed at least one csDMARD and received standard of care medications were included. A Sankey diagram was used to show the treatment trajectory of all subjects. When considering the highest line of treatment achieved, only patients completing the study to week 96 were included. Test of equality of proportions for categorical variables were performed using the Chi-Square test. Results: A total of 218 patients met the inclusion criteria, and 40 patients were withdrawn by 96 weeks. Treatment trajectories for these 218 subjects are illustrated in Figure 1 using a Sankey diagram, displaying the proportion of patients on each medication over time. The 178 patients who completed the 96 weeks follow-up were categorized based on the highest line of treatment received at any time during the study period. 21 (11.8%) were never treated with DMARD therapy (due to mild disease, patient preference, pregnancy) and 78 (43.8%) were treated with a single csDMARD only over the 96 weeks follow up. During the same period, 65 (36.5%) were prescribed more than one csDMARD, while 14 (7.9%) went directly to a bDMARD after first csDMARD failure, due to contraindications to csDMARDs or axial involvement. Of the 65 patients who received more than one csDMARD, 30 (46.2%) were switched to a second csDMARD and 32 (49.2%) received combination csDMARD therapy after first csDMARD failure. Some had more aggressive treatment, with 3 (4.6%) patients prescribed combination csDMARD therapy at diagnosis. Of the 35 patients receiving two csDMARDs concomitantly, 10 (28.6%) continued combination csDMARDs to week 96, 8 (22.9%) reduced therapy and 17 (48.6%) escalated to receive a bDMARD. The proportion of patients who eventually received a bDMARD was similar between patients who switched to a second csDMARD and those on combination csDMARD therapy (14 (46.7%) vs 17 (48.6%), respectively; p=0.878). The average time between the start of second-line treatment and bDMARD initiation was also similar in these groups; 198 days (standard deviation: 88) for patients on a second single csDMARD and 178 days (standard deviation: 110) for patients on combination csDMARD therapy. To assess whether patients were adequately treated or if therapy should have been escalated, we looked at the proportion of patients achieving minimal disease activity (MDA) at 48 weeks. Among patients receiving combination csDMARD therapy, 63.6% (7/11) achieved MDA, compared to 27.3% (3/11) of those prescribed a bDMARD following combination therapy (p=0.0867). Interestingly, only 38.9% of patients discontinued their combination therapy due to lack of efficacy, while the 61.1% discontinued due to side effects. Conclusion: Our study supports combination csDMARD therapy as a valid treatment option in PsA, as only about half of those treated with this strategy later required a bDMARD. Clinical data also implies that patients on combination csDMARD therapy were not undertreated, as the majority were in MDA at 48 week follow up. Further analyses are required to confirm the efficacy, feasibility and safety of combination csDMARD therapy. Figure 1Sankey diagram of treatment trajectories of patients in the MONITOR-PsA cohort over 96 weeks, shown with percentages at each time points. REFERENCES: NIL . Acknowledgements: The study is funded as part of a National Institute for Health Research Clinician Scientist award awarded to LC (ref CS-2016-16-016) through the University of Oxford. The research is supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC). The study was also funded by Janssen and UCB Bopharma SRL. Disclosure of Interests: Raphaël Hurtubise Biojamp, Celltrion, UCB, Jean-Guillaume Letarouilly Abbvie, Amgen, Biogen, BMS, Galapagos, Janssen, Lilly, Novartis, and Pfizer, AbbVie, Celltrion, Janssen, and MSD, Pfizer, Elnaz Saeedi: None declared, Lija James: None declared, Nicola Gullick AbbVie, Celgene, Eli Lilly, Janssen, Novartis and UCB, AbbVie, Alfasogma, Celgene, Eli Lilly, Janssen, Novartis, and UCB, Abbvie, Astra Zeneca, Eli Lilly, Galapagos, Izana and Novartis, Anne Francis: None declared, William Tillett AbbVie, Amgen, Bristol Myers Squibb, Celgene, Eli Lilly, GSK, Janssen, Novartis, Ono-Pharma, Pfizer and UCB, AbbVie, Amgen, Bristol Myers Squibb, Celgene, Eli Lilly, GSK, Janssen, Novartis, Ono-Pharma, Pfizer and UCB, m Abbvie, Celgene, Eli Lilly, Janssen, Pfizer and UCB, Yvonne Sinomati: None declared, Laura Tucker: None declared, Nadia Mian: None declared, Sofia Massa: None declared, Laura C. Coates AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB, AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Enlivex, Janssen, Moonlake, Novartis, Pfizer, Takeda and UCB, Abbvie, Amgen, Janssen and UCB. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.