Methotrexate Efficacy in the Tight Control in Psoriatic Arthritis Study

Methotrexate (MTX) is a commonly used disease-modifying antirheumatic drug in psoriatic arthritis, but there is conflicting evidence to support its efficacy.

Within the Tight Control of Psoriatic Arthritis (TICOPA) study, patients were treated with MTX as part of the tight control protocol or standard care. Outcomes were recorded at the 12-week visit, including joint counts, skin, nail, enthesitis, dactylitis, and patient-reported measures.

Of the 206 patients enrolled, 188 received MTX in the first 12 weeks of the trial with 104 receiving a mean dose > 15 mg/week. The proportions of patients achieving the American College of Rheumatology (ACR) outcomes at 12 weeks were ACR20 40.8%, ACR50 18.8%, and ACR70 8.6%, with 22.4% achieving minimal disease activity. Improvements were seen in psoriasis with 27.2% reaching a Psoriasis Area and Severity Index (PASI) 75. The proportion of patients with dactylitis and Leeds dactylitis instrument (LDI) scores decreased significantly (62.7% decrease in patients with dactylitis, median change LDI -59.7, -157.4 to -26.4, p = 0.033). The decrease in proportion of patients with enthesitis (25.7%) was significant, but the median change in enthesitis score was 0. There was a trend to higher proportions of patients receiving over 15 mg/week achieving ACR20, ACR50, and PASI75.

Despite the open-label design of the data, improvements in multiple clinical outcomes were seen. The proportion of patients reaching ACR20 in the TICOPA study was higher than in the Methotrexate in Psoriatic Arthritis study (41% vs 34%), but no comparative data are available for other outcomes. There is a suggestion of a dose response, but this is hard to assess when patients doing well may be maintained on lower doses.