SAT0556 Methotrexate Efficacy in Early Psoriatic Arthritis – Open Label Data from the Ticopa Study

BackgroundMethotrexate (MTX) is a common first line DMARD in psoriatic arthritis (PsA) but until recently no RCTs evaluating its efficacy in PsA were available. The MIPA trial found no significant difference in arthritis outcomes at 6 months but was criticised as the target dose was only 15mg.ObjectivesThe aim of this analysis was to investigate clinical outcomes in patients with early PsA treated with MTX in the TICOPA study.MethodsWithin the Tight Control of Psoriatic Arthritis, patients (in either arm) could be treated with methotrexate. All patients in the tight control arm received MTX as first line monotherapy for the first 12 weeks while patients in the standard care arm the majority of the patients in the standard care arm also received MTX. Clinical outcomes were recorded at the 12 week visit including joint counts, PASI, NAPSI, enthesitis and dactylitis measures.ResultsOf the 206 patients enrolled in TICOPA, 188 received oral methotrexate in the first 12 weeks of the trial. Of these, 175 patients reached a dose of at least 15mg by 12 weeks, with 122 reaching a dose of at least 20mg and 86 reaching the top dose of 25mg.The proportions of patients achieving the ACR outcomes at 12 weeks were ACR20 40.8%, ACR50 18.8% and ACR70 8.6% with 22.4% achieving minimal disease activity (MDA). Improvements were also seen in PASI scores with 27.2% reaching a PASI75. For those with enthesitis at baseline (n=148) the median change in enthesitis score was 0 (IQ range -1, 0 for LEI and IMPACT, -2, 1 for MASES). For those with baseline dactylitis (n=59), there was a median change in LDI scores of -59.7 (-157.4, -26.4). 117 patients had nail involvement and these patients showed a median change in mNAPSI score of -2 (IQ range -8, 0) with changes more commonly in the nail bed due to the short follow up time.Slightly higher proportions of patients receiving 180mg MTX or more over the 12 week period (equivalent to an average of 15mg per week) achieved ACR20, 50 and PASI 75 but the numbers were small so this did not reach significance.ConclusionsDespite this data being open-label, it does show improvements in multiple clinical outcomes associated with MTX use in PsA. The proportion reaching ACR20 is slightly higher than that in MIPA (41 vs 34%) but no comparative data are available for the other outcomes. There is a suggestion of better responses with doses above 15mg per week but the dose-response is harder to assess in such a study where confounding exists as patients