Adalimumab with Methotrexate vs. Adalimumab Monotherapy in Psoriasis: First-Year Results of a Single-Blind Randomized Controlled Trial

INTRODUCTION: Adalimumab is normally prescribed with methotrexate (MTX) in rheumatoid arthritis given the enhanced treatment effect and reduced antidrug antibody formation compared with adalimumab monotherapy (ADL). In psoriasis, the long-term treatment effects and pharmacokinetic profile have not been investigated extensively. METHODS: We conducted a randomized controlled trial to assess the efficacy, safety, pharmacokinetics, and immunogenicity of adalimumab combined with MTX 10 mg per week (ADL-MTX group) compared with that of ADL (ADL group) in chronic plaque psoriasis. RESULTS: A total of 31 patients in the ADL-MTX group and 30 in the ADL group were analyzed. After 1 year, a (nonsignificant) better drug survival was found in the ADL-MTX group (74.2 vs. 58.6%, P = 0.15). The PASI 75 response in week 49 was 58.1 versus 36.7% (P = 0.13), and the median (interquartile range) serum-trough concentrations were 6.8 (5.5‒9.2) versus 5.9 (3.5‒8.8) mg/l (P = 0.26) in the ADL-MTX group and ADL group, respectively. Fewer patients showed antidrug antibodies in the ADL-MTX group (22.6 vs. 60.0%, P < 0.01). No serious adverse events occurred. CONCLUSION: Combination therapy of adalimumab and MTX results in fewer patients showing antidrug antibodies, with a trend toward a better PASI 75 response, drug survival, and higher serum-trough concentrations than ADL. Patient-reported outcomes and adverse events were comparable between the groups.