Does concomitant methotrexate with adalimumab influence treatment outcomes in patients with psoriatic arthritis? Data from a large observational study

Objective. To examine the influence of concomitant methotrexate (MTX) with adalimumab (ADA) on outcomes in patients with psoriatic arthritis (PsA) using data from an observational study of ADA. Methods. Data from a German noninterventional study of patients with PsA starting treatment with ADA were analyzed retrospectively for effects of concomitant MTX on key outcomes, including Disease Activity Score-28 joints, tender and swollen joint counts, skin assessments, and safety. Patients were categorized into those with symptoms of axial involvement and those with no symptoms of axial involvement as judged by the examining clinician. Results. A total of 1455 patients met the study criteria, 296 with axial involvement (ADA monotherapy = 165 plus MTX = 131) and 1159 with no axial involvement (ADA monotherapy = 658 plus MTX = 501). ADA, alone or combined with MTX, resulted in strong and comparable reductions in disease activity measures in patients with and those without axial disease over 24 months of therapy. In multiple regression analyses, concomitant MTX did not affect joint or skin outcomes in either the group with axial manifestations or the group without axial disease. Neither adverse event rates nor withdrawal rates were significantly influenced by concomitant MTX. Conclusion. ADA is an effective treatment option for patients with PsA with or without axial involvement. Compared with ADA monotherapy, the use of concomitant MTX with ADA does not improve articular or skin outcomes in patients with PsA regardless of axial symptoms.