Methotrexate efficacy and tolerance in plaque psoriasis. A prospective real-life multicentre study in France.

Background: Methotrexate (MTX) is a major systemic treatment for moderate to severe plaque psoriasis. A randomized trial has recently been published evaluating a single weekly dosage (17.5mg), but few prospective real-life data are available. The main objective of this study was to prospectively evaluate the efficacy of MTX in real-life. The secondary objectives were to evaluate predictive parameters for treatment efficacy and the frequency of adverse events.

Patients And Methods: A prospective cohort involving consecutive at in 25 centres belonging to GEM RESOPSO included all adults with plaque psoriasis in whom MTX treatment was initiated. The efficacy criterion was achievement of PASI 75 at week (W) 12/16. The impact of demographic data, psoriasis characteristics (duration, topography, rheumatism), dosage (W12/16 dosage, cumulative dose after 4 weeks), and mode of administration (subcutaneous vs. oral, concomitant use of folic acid) on efficacy was evaluated. Intention-to-treat (ITT),per protocol (PP), and multivariate analyses were performed.

Results: Two hundred and fifty-six patients (F/M: 105/151; mean age: 45.0 years; rheumatism: 12.6%) with plaque psoriasis were included. 99 patients were not analysed at W12/16 (16 because of inefficacy, 16 because of intolerance, 56 were lost to follow-up or had data missing). PASI 75 was achieved in 98 patients, with efficacy of 38.3% in the ITT analysis and 58.3% in the PP analysis. In the ITT analysis, absence of previous use of cyclosporine (P=0.01) and a cumulative dose of MTX>60mg after 4 weeks (P<0.0001) were associated with higher PASI 75 rates. In the PP analysis, only absence of previous use of cyclosporine (P=0.0009) was associated with a better PASI 75 results. There was no association between PASI 75 and patient characteristics (including body mass index), clinical aspects of psoriasis, route of administration, combination with folic acid, or W12/16 dose. Adverse events were reported by 34.8% of patients. These consisted mainly of digestive disorders (nausea, abdominal pain), asthenia and moderate hepatic cytolysis. The frequency of adverse events was correlated with methotrexate dosage.

Discussion: The efficacy of MTX in plaque psoriasis in this real-life study of 256 patients is consistent with the data in the literature, including the recently published randomized trial (41% PASI 75). This rate was unaffected by patient weight, route of administration and combined use of folic acid. Absence of previous use of cyclosporine appears to be associated with better efficacy although there is no clear explanation for this. The initial dosage (high dose in the first month) appears to be associated with superior efficacy for W12/W16.