Long-term experience with etanercept in the treatment of rheumatoid arthritis in elderly and younger patients - Patient-reported outcomes from multiple controlled and open-label extension studies

Background: The impact of long-term therapy for rheumatoid arthritis (RA) in elderly (>= 65 years of age) and younger (< 65 years of age) patients, especially on patient-reported outcomes, has not been well studied. We evaluated patient-reported outcomes in elderly patients treated with etanercept, in contrast to outcomes in younger patients, using data from multiple controlled and open-label extension studies of patients with early RA (ERA; <= 3 years) and late RA (LRA; disease-modifying antirheumatic drug [DMARD]-refractory RA). Methods: This post hoc analysis included adult patients with RA enrolled in controlled, double-blind studies (up to 2 years) and subsequent open-label extension studies (up to 4 years). Patients were evaluated according to age at baseline of the original study. Patients may have received etanercept, placebo or methotrexate during the blinded treatment phases, but all patients had been receiving etanercept 25mg twice weekly for at least 4 years. Both ERA and LRA extension studies are ongoing. Patient-reported outcome assessments included improvement in Health Assessment Questionnaire - Disability Index (HAQ-DI), proportions of patients achieving an improvement in HAQ-DI >= 0.22 points, patients exhibiting worsening of HAQ-DI and patients achieving an HAQ-DI score of 0. Results: Elderly patients, with either ERA or LRA, had significantly worse baseline mean HAQ-DI scores than younger patients (p < 0.05, Student's t-test) in most studies, indicating greater disability. Improvement in HAQ-DI was greatest during the first 3 months after starting etanercept treatment in the controlled phase and appeared to be sustained over 3-6 months in patients with early or DMARD-refractory RA. Across the various controlled trials, mean improvements from baseline in HAQ-DI ranged from 0.39 to 0.92 points in elderly patients and from 0.57 to 1.00 points in younger patients. Patients with ERA and LRA, regardless of age group, maintained their improvement in HAQ-DI throughout the open-label extension trials for up to a total of 6 years of etanercept therapy. Change from baseline in HAQ-DI was moderately correlated with 28-joint Disease Activity Score within each age group across the multiple trials. Conclusion: Both elderly and younger patients with RA treated with etanercept exhibited similar and rapid improvements in functional status during controlled studies, and these improvements were sustained during open-label extension trials.