Background MTX is recommended as the first DMARD in rheumatoid arthritis. Despite its widespread use and more than two decades of experience, considerable variations exist among rheumatologists in prescribing MTX.
Objectives To describe symptomatic and structural impact of different profiles of MTX regimen in early arthritis (EA) in daily clinical practice.
Methods – Patients: from the French cohort of EA ESPOIR (at least 2 swollen joints for less than 6 months, DMARD naïve), fulfilling the ACR-EULAR criteria for RA at baseline, and treated by MTX as first DMARD during follow-up
– Treatment groups: MTX optimal regimen was defined 1] by the delay of introduction (within 1, 3 and 4 months after the baseline visit of the ESPOIR cohort) AND 2] by the dose: dose of initiation at least 10 mg/week and achieving at least 20 mg/w or 0.3mg/kg/w if DAS28 >2.6 as noticed at the 6 months visit of the ESPOIR cohort (or any dose noticed at month 6 in case of DAS<2.6). Sensitivity analysis on different target dose (at least 0.2mg/kg/w) was performed.
– Outcomes: remissions (Boolean, SDAI and DAS28), functional stability (HAQ≤0.5 and deltaHAQ≤0.25) and absence of radiographic progression (delta Sharp score<1) after 1 and 2 years of follow-up.
– Analyses: outcomes of patients receiving MTX with versus without optimal regimen were compared by chi square test. Evaluation of the symptomatic and structural efficacy has been performed by logistic regression (after adjustement on: SJC, CRP, ACPA or RF, Erosion, Center, Age, Smoking, HAQ, ACR1987 criteria).
Results 352 out of 600 RA patients received MTX as first DMARD with a mean dose of MTX =13.1±3.9 mg/week within the first year of follow-up. Overall, MTX was initiated within 1 month after baseline in 53.7% of patients, within 3 months in 76.1% and within 4 months in 81%. There were no differences in remission rates, functional capacity and structure with regard to such time of introduction of MTX. In all, 25.3% were treated initially with a weekly dose of at least 10 mg/week and with dose escalation to least at 20 mg/w or 0.3mg/kg/w as noticed at months 6 if DAS28>2.6. Both remission (whatever the definitions used), and functional stability were more frequently observed in the “optimal” MTX regimen (boolean remission: 27.4% versus 10%; OR at year 1 =2.53 [1.21 -5.28] and functional stability: 74% versus 52.6%; OR at year 1 =3.04 [1.51 -6.14]) but without significant impact on radiographic progression over 2 years (34.9% versus 35.2%, OR at 1 year =1.08 [0.57-2.04]). Results were similar at 2 years. These favorable clinical outcomes were not observed with the target dose of at least 0.2mg/kg/w.
Conclusions The most important aspect of the MTX optimal regimen is the escalation to least at 20 mg/w or 0.3mg/kg/w if DAS28 remission is not reached.
Disclosure of Interest : None declared