The objective of these posthoc analyses was to evaluate short-term clinical outcomes as predictors of poor response after 1 year of treatment with combination etanercept/methotrexate (ETN/MTX) therapy versus MTX monotherapy in patients with early rheumatoid arthritis (RA).
Participants with moderate to severe RA [28-joint Disease Activity Score-Erythrocyte Sedimentation Rate (DAS28-ESR) ≥ 3.2] of 3-24 months' duration received ETN 50 mg weekly plus MTX or MTX monotherapy for 52 weeks. Regression analyses were performed to evaluate the likelihood of remission (DAS28-ESR < 2.6) after 1 year despite poor clinical short-term treatment effects (e.g., absolute or changes from baseline in DAS28-ESR after 4, 8, 12, 20, and 24 weeks of therapy).
The magnitude of disease activity and its improvement and timing influenced remission probability in both treatment groups; remission rate was diminished with higher disease activity levels and lower response levels over time from weeks 4 to 24. The rate of DAS28-ESR remission at 1 year was generally greater with ETN/MTX than with MTX alone at most timepoints from weeks 4 to 24. Despite persistent high disease activity (DAS28-ESR > 5.1) after 4, 8, 12, and 24 weeks of therapy, 35%, 27%, 25%, and 22% of patients, respectively, in the ETN/MTX group achieved DAS28-ESR remission after 1 year of continuous treatment; the respective proportions were 33%, 27%, 8%, and 13% in the MTX group.
High disease activity and less improvement with treatment over time in the initial 24 weeks of treatment, particularly after 12 weeks, were predictive of a lower remission rate after 1 year.