Age

18–any

Sex

ALL

Healthy volunteers

Not accepted

Patient aged over 18 years
Patient with Rheumatoid Arthritis according to the 2010 ACR/EULAR criteria
Patient meeting the criteria for initiation of a JAK inhibitor according to the marketing authorization and international recommendations
Patient capable of providing informed, written, dated, and signed consent before the start of any trial-related procedure.

No contraindication to a bDMARD
Not stable dose of corticosteroids in the 4 weeks preceding enrollment
Not stable dose of maintenance therapy (methotrexate, leflunomide, hydroxychloroquine, cyclosporine, gold salts) in the 4 weeks preceding enrollment
Prior treatment with a JAK inhibitor
Patient unable to be followed-up in the study during 6 months
Minors or adults under guardianship or curatorship, or deprived of their liberty
Pregnant or breastfeeding patient
Patient refusing to use an effective method of contraception for the duration of the study
Person not affiliated with a social security scheme.

Comparison of Oral Administration of a JAK Inhibitor in Rheumatoid Arthritis