Final 10-year effectiveness and safety results from study DE020: adalimumab treatment in patients with rheumatoid arthritis and an inadequate response to standard therapy

Objective: To evaluate the long-term effectiveness and safety of 10 years of adalimumab (ADA) treatment in DMARD-refractory RA patients and to analyse efficacy based on RF status and baseline disease duration.

Methods: DE020 was a multicentre, phase 3, open-label continuation study. Adult RA patients who received s.c. ADA (40 mg every other week or monthly) in one of four early assessment studies could receive ADA for ≤10 years in DE020. Assessments included the 28-joint DAS with CRP (DAS28-CRP), Simplified Disease Activity Index (SDAI), HAQ Disability Index (HAQ-DI) and safety as events per 100 patient-years.

Results: Of 846 enrolled patients, mean age at baseline was 55.6 years, 78.1% were women, mean disease duration was 11.7 years and 27.0% were RF(-). Among 286 (33.8%) patients who completed 10 years of ADA, 168/236 (71.2%) achieved DAS28-CRP ≤3.2, 101/238 (42.4%) achieved HAQ-DI <0.5 and 90/241 (37.3%) achieved DAS28-CRP ≤3.2 plus HAQ-DI <0.5. DAS28-CRP- or SDAI-based remission was observed in 135/236 (57.2%) and 70/236 (29.7%) patients, respectively. Effectiveness outcomes were similar regardless of RF status. Higher proportions of patients with shorter vs longer baseline disease duration (≤2 vs >2 years) achieved HAQ-DI <0.5 (60.6% vs 39.5%; P = 0.023) and DAS28-CRP ≤3.2 plus HAQ-DI <0.5 (58.1% vs 32.5%; P = 0.006). Adverse events (317.2 events per 100 patient-years) during ADA exposure were consistent with the expected safety profile for TNF inhibitors.

Conclusion: ADA led to sustained clinical and functional responses in the 33.8% of treatment-refractory RA patients who completed 10 years of treatment. Patients with shorter disease duration achieved better outcomes, highlighting the need for early treatment. No unexpected safety findings were observed.

Trial registration: ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT00195650.