Objective: We evaluated patient drug adherence to and efficacy and safety of adalimumab (ADA) based on data collected from approximately 200 patients to retrospectively examine the best use of ADA in Japanese patients with longstanding rheumatoid arthritis (RA) managed in daily practice.
Methods: For explorative comparisons, patients were stratified by prior use or no use of biologics (Bio-naïve vs. Bio-switch) and concomitant use (+) or no use (-) of methotrexate (MTX) into four subgroups. The primary efficacy endpoint was extent of improvement in the Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR) from baseline to 24 weeks assessed as European League Against Rheumatism (EULAR) good response. Secondary endpoints included ADA treatment continuation as represented by Kaplan-Meier survival curves and percentages of patients achieving remission as defined by DAS28-ESR <2.6.
Results: Overall, mean DAS28-ESR significantly decreased from 5.6 ± 1.2 at baseline to 4.1 ± 1.7 at week 24 (p < 0.0001), and >30 % of patients achieved EULAR good response. Subgroup analyses indicated that patients in the Bio-naïve and MTX (+) subgroup showed the highest EULAR good response rate of 37.3 % at week 24. The three most commonly reported adverse events (AEs) were skin allergies such as injection-site reactions, infections, and respiratory disorders such as interstitial lung lesions and organizing pneumonia.
Conclusion: In conclusion, ADA therapy resulted in significant clinical response in established Japanese patients with RA treated in daily practice. It also demonstrated generally good safety and tolerability. It was suggested that the best use of ADA may be in biologically naïve patients with concomitant administration of MTX.