Role of Methotrexate in the Management of Psoriatic Arthritis.

Methotrexate is known to be safe and efficacious in the management of rheumatoid arthritis and psoriasis and thus has been used for the management of psoriatic arthritis despite a lack of evidence to support efficacy in psoriatic arthritis from randomized controlled trials. Although the largest randomized trial to date did not support its use as a disease-modifying therapy, observational studies have supported its role, and current treatment recommendations approve of its use as a first-line agent for the management of psoriatic arthritis with predominant peripheral arthritis. The first treat-to-target study in psoriatic arthritis, comparing tight control with standard care, has shown the efficacy of methotrexate as monotherapy in the first 12 weeks. This trial demonstrated the effectiveness of methotrexate with improvement in peripheral arthritis, skin and nail disease, enthesitis, and dactylitis over the course of 12 weeks. There is conflicting evidence about the role of combination (concomitant methotrexate and anti-tumor necrosis factor) therapy. However, drug survival and immunogenicity of certain anti-tumor necrosis factors seem to be better when used in combination with methotrexate. This report reviews the available evidence on the efficacy and effectiveness of methotrexate in psoriatic arthritis and its role in treating psoriatic arthritis to target, as well as in combination with biologic agents. Ideally, randomized placebo-controlled clinical trials evaluating methotrexate (using subcutaneous route of delivery) would provide much-needed clarity on the role of methotrexate in the management of psoriatic arthritis; however, issues around using a placebo in patients with active psoriatic arthritis may render such a trial unfeasible.