Etanercept is effective as monotherapy or in combination with methotrexate in rheumatoid arthritis: subanalysis of an observational study

Markus Gaubitz, Karl-Heinz Göttl, Olaf Behmer, Ralph Lippe, Thomas Meng, Peter-Andreas Löschmann

Approximately 30% of patients with rheumatoid arthritis receiving biological disease-modifying antirheumatic drugs (bDMARDs) take them as monotherapy. Although etanercept (ETN) monotherapy has been evaluated in clinical trials, data in the real-world setting are sparse. We compared the efficacy and safety of ETN, given alone or in combination with methotrexate (MTX), in routine clinical practice. This was a subanalysis of patients who received either ETN alone or ETN + MTX during a 52-week prospective, observational study conducted at 329 German centers. The primary endpoint was "Funktionsfragebogen Hannover" (Hannover Functional Ability Questionnaire [FFbH]; low FFbH = worse function) functional remission at week 26 and week 52. Secondary endpoints included the 28-joint count Disease Activity Score (DAS28), DAS28 remission (DAS28 < 2.6), and adverse events (AEs). Participating centers applied ETN monotherapy in 43.1% of patients and ETN + MTX in 56.9%. A smaller proportion of patients achieved FFbH functional remission with ETN vs ETN + MTX (31.9%, 95% confidence interval [CI] 29.1-34.9% vs 39.8%, 37.2-42.5%, respectively; p < 0.001) at 26 weeks and at 52 weeks (38.4%, 35.1-41.7% vs 44.3%, 41.5-47.2%, respectively; p = 0.007). After 52 weeks, the mean DAS28 (±SD) decreased from 5.5 ± 1.3 to 3.4 ± 1.4 (ETN) vs 5.3 ± 1.3 to 3.2 ± 1.3 (ETN + MTX) and DAS28 remission was achieved by 32.5% (95% CI 29.0-36.1%) of patients with ETN vs 38.8% (35.8-41.9%; p = 0.007) with ETN + MTX. Overall, 20.6 (ETN) and 19.7% (ETN + MTX) of patients reported treatment-related AEs. Patients received ETN monotherapy almost as often as ETN + MTX. ETN + MTX appeared marginally more effective than ETN monotherapy in some, but not all, outcomes measured.