Background:Methotrexate (MTX) is the gold standard treatment for rheumatoid arthritis (RA). The international guidelines recommend optimizing its dose before the introduction of a biologic treatment in cases where it is well tolerated1.Objectives:The objective of this study is to evaluate the dose of MTX before the initiation of biological treatment in RA patients with MTX ineffectiveness.Methods:This is a multicenter, cross-sectional, prospective study including adults RA, over a period of 6 months (January-June 2019). We collected the following data: sex, age, comorbidities (diabetes, hypertension), rate of RF and ACPA, dose of MTX, rate of patients on corticosteroids, Disease Activity Score (DAS 28-vs), Health Assessment Questionnaire (HAQ) and SHARP Score.Results:Number of patients: 239 (187 women / 52 men); average age: 48.3 years (19 - 81); average duration of the disease: 13.6 ± 8.2 years. Comorbidities: arterial hypertension (14,6 %) - diabetes (13 %),The RF were positive in 59.8%. The average value of ACPA is 228.76 ± 287.08 IU / L, positive in 73% case. The average DAS28vs is 4.77 ± 1.46 (0.77 - 12.26). The average modified SHARP 111.67 ± 98.16 (0-448), the average HAQ is 1.13 ± 0.82 (0 - 2.87). 86.7% of patients are under corticosteroids.Only 18.5% of patients had a dose of MTX between 20 and 25 mg / week. the remaining 82% of patients the average dose of MTX was 14 mg / week (10-18.5).Conclusion:These results suggest that the dose of MTX was not optimized before the initiation of biotherapy in the majority of patients with RA.References:[1]Smolen JS, Landewé R, Bijlsma J, et al.EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 updateAnnals of the Rheumatic Diseases2017;76:960-977.[3]Claire Daiena, Charlotte Huac, Cécile Gaujoux-Viala, et al. Update of French society for rheumatology recommendations for managing rheumatoid arthritis. Joint Bone Spine 86 (2019) 135–150[2]Singh JA, Saag KG, Bridges SL Jr, et al. 2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis. Arthritis Care Res. 2016 Jan;68(1):1-25.Disclosure of Interests:None declared