Factors Associated With Maintenance of Remission Following Change From Combination Therapy to Monotherapy in Patients With Rheumatoid Arthritis.

Abstract

Some patients with rheumatoid arthritis (RA) who persist in remission may decide to stop their therapy. We evaluated baseline characteristics associated with remaining in remission or low disease activity (LDA) following medication withdrawal. The Study of Etanercept and Methotrexate in Combination or as Monotherapy in Subjects With Rheumatoid Arthritis (SEAM-RA) was a phase III, multicenter, randomized withdrawal, double-blind, controlled study in patients with RA on methotrexate (MTX) + etanercept (ETN). If remission (Simplified Disease Activity Index [SDAI] ≤ 3.3) was sustained through a 24-week run-in period, patients then entered a 48-week double-blind period and were randomized 2:2:1 to receive MTX monotherapy, ETN monotherapy, or continue combination therapy. Multivariate logistic regression analysis was performed to identify baseline factors associated with remission or LDA at the end of both periods. Of 371 patients enrolled, 253 entered the double-blind period. After adjusting for other factors, covariates associated with achieving SDAI remission at the end of the run-in period included younger age, longer duration of MTX treatment, and less severe clinical disease variables. Covariates associated with maintaining remission/LDA at the end of the 48-week double-blind period included lower patient global assessment of disease activity (PtGA), lower C-reactive protein, rheumatoid factor (RF) negativity, longer RA duration in the MTX arm, shorter duration of ETN treatment, and lower magnesium. These findings indicate patients with overall lower disease activity are more likely to remain in SDAI remission/LDA after switching from combination therapy to monotherapy. RF-negative status and lower PtGA scores were strongly associated with increased likelihood of remaining in remission/LDA with MTX or ETN monotherapy. (SEAM-RA; ClinicalTrials.gov: NCT02373813).