Effectiveness and safety of biologic and targeted synthetic disease-modifying anti-rheumatic drugs in elderly patients with rheumatoid arthritis: real-world data from the KOBIO Registry

We aimed to evaluate the clinical outcomes and safety of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) and to identify predictors of treatment responses to b/tsDMARDs in elderly patients with rheumatoid arthritis (RA).Data from the nationwide cohort of elderly (≥ 65 years) patients enrolled in the KOBIO Registry were analysed. Clinical outcomes were assessed, including changes in the Simplified Disease Activity Index, after treatment. Adverse events and reasons for drug discontinuation were assessed. Multivariable logistic regression analyses were performed to determine which baseline variables affected treatment responses and adverse events (AE).Elderly patients treated with b/tsDMARDs (n=355) or conventional synthetic DMARDs (csDMARDs) (n=104) were included. The median age was 70 years and 77% were female. After 1 year, 63% of patients in the b/tsDMARD group and 68% in the csDMARD group achieved remission or low disease activity (LDA). Overall, 27% of patients in the b/tsDMARDs group and 24% in the csDMARDs group experienced AE. A total of 43.4% of patients on b/tsDMARDs discontinued therapy due to lack of effectiveness (27%), AE (34%), or other reasons (35%). The estimated median retention of b/tsDMARDs was 2.5 years. Male sex and non-exposure to tobacco at baseline were independent factors associated with achieving remission or LDA after 1 year. Interstitial lung disease (ILD) was the most prominent comorbidity associated with AE.Treatment with b/tsDMARDs is effective and well tolerated in elderly patients with RA; nonetheless, ILD is a key comorbidity that should be monitored carefully.