FRI0360 IMPACT OF METHOTREXATE ON DISEASE PATTERN IN ACTIVE PSORIATIC ARTHRITIS PATIENTS ELIGIBLE FOR A RANDOMIZED CLINICAL TRIAL WITH USTEKINUMAB: COMPARATIVE BASELINE DATA FROM MULTICENTRE INVESTIGATOR-INITIATED MUST TRIAL
Authors: T. Rossmanith, M. Köhm, U. Kiltz, J. Rech, G. R. Burmester, H. Kellner, A. Bulczak-Schadendorf, A. C. Foldenauer, H. Burkhardt, F. Behrens
Journal: Annals of the Rheumatic Diseases (2020)

Background: Methotrexate (MTX) is a csDMARD treatment that is initiated as first-line therapy (after NSAID) in active psoriatic arthritis (PsA). Randomized clinical trials mostly require treatment failure or intolerance of csDMARD/MTX therapy before initiation of a biological treatment. We designed an investigator-initiated (IIT) randomised blinded study comparing PsA patients starting open label Ustekinumab (UST) combined with blinded MTX or placebo (PLC). Patients are stratified regarding their previous MTX therapy (continuation or discontinuation of MTX (MTX-pre-treated patients –group A) or newly initiate MTX or continue without MTX (MTX-naïve patients – group B). Objectives: To determine disease characteristics of patients with active psoriatic arthritis regarding their skin and musculoskeletal manifestations in dependence of their MTX treatment status. Methods: A total of 186 patients with active PsA (defined as TJC ≥4, SJC ≥4 (68/66 joint count) and DAS28 ≥ 3,2) were screened for eligibility. At baseline (BL) 173 patients starting open label UST were randomised to receive either MTX or PLC. At Screening (SCR) and BL, demographic data, PsA and PsO disease activity (joint count (TJC/SJC), enthesitis (LEI), dactylitis (number of digits), PASI, BSA, mtNAPSI), previous medication as well as quality of life (QoL) and function (documented as PRO using DLQI, HAQ and subjects assessment of pain as visual analogue scale (VAS) was documented. Results: Our preliminary blinded data export comprised all documented and released data for SCR and BL until Mid-January 2020 - in total 154 randomized patients. Thereof, 78 patients were randomized in group A and 76 in group B. BL characteristics were well balanced between groups (mean age A: 50,7 years vs. 46,4 in B, BMI 29 vs. 29,6 in B). More male were included in B (72% vs. 50 %). In median, patients in A had a disease duration of 2,9 y whereas duration in B was in median 0,3 y. More patients in A had failed previous biological therapy (17 to 6 in B), discontinued due to intolerability or ineffectiveness as allowed for study inclusion. Mean DAS28 was 4,5 (moderate disease activity) for both groups and mean values for SGA, PGA were comparable (SGA: 59,1 vs 54,9 PGA: 61,4 vs. 55.6) reflecting comparable disease activity in peripheral arthritis. Mean LEI was comparable in both groups (A: 1,3 vs B: 1,1). Mean number of digits with dactylitis were slightly higher in B (0,8) than in A (0,2). Overall HAQ showed no differences (1.0 in B vs. 0.8 in A – missing data 45 and 29 resp.) and pain VAS did not differ between groups (A: 54,9 mm vs. 56,6 mm in B). PASI and NAPSI were higher in B at BL than in group A (PASI: 7,2 vs. 3,3, mtNAPSI 5,0 vs. 3,0) and PRO showed a higher skin disease burden experienced by MTX-naïve patients prior randomization: in DLQI more patients on MTX experience “no effect” of their skin disease on QoL (22% vs. 7%) whereas more MTX naïve patients see a “moderate” “large” to “extreme large effect” of their disease on QoL (16%, 11%, 5% in B vs. 10%, 8%, 3% in A). Conclusion: Our results give important information about comparability of patient population on MTX or without MTX therapy eligible for biological trials. Despite a comparable disease activity in peripheral arthritis scores, skin disease activity was increased in patients without MTX compared to MTX treated patients. Number of affected digits in dactylitis was lower with MTX, whereas its impact on enthesitis seems to be neglectable. Disclosure of Interests: Tanja Rossmanith Grant/research support from: Janssen, BMS, LEO, Pfizer, Michaela Köhm Grant/research support from: Pfizer, Janssen, BMS, LEO, Consultant of: BMS, Pfizer, Speakers bureau: Pfizer, BMS, Janssen, Novartis, Uta Kiltz Grant/research support from: AbbVie, Amgen, Biogen, Novartis, Pfizer, Consultant of: AbbVie, Biocad, Eli Lilly and Company, Grünenthal, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, MSD, Novartis, Pfizer, Roche, UCB, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Gerd Rüdiger Burmester Consultant of: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Speakers bureau: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Herbert Kellner: None declared, Anita Bulczak-Schadendorf Grant/research support from: Janssen, Ann Christina Foldenauer: None declared, Harald Burkhardt Grant/research support from: Pfizer, Roche, Abbvie, Consultant of: Sanofi, Pfizer, Roche, Abbvie, Boehringer Ingelheim, UCB, Eli Lilly, Chugai, Bristol Myer Scripps, Janssen, and Novartis, Speakers bureau: Sanofi, Pfizer, Roche, Abbvie, Boehringer Ingelheim, UCB, Eli Lilly, Chugai, Bristol Myer Scripps, Janssen, and Novartis, Frank Behrens Grant/research support from: Pfizer, Janssen, Chugai, Celgene, Lilly and Roche, Consultant of: Pfizer, AbbVie, Sanofi, Lilly, Novartis, Genzyme, Boehringer, Janssen, MSD, Celgene, Roche and Chugai