Sustained Long-Term Retention Rates of Abatacept in Combination with Conventional Synthetic Disease-Modifying Antirheumatic Drugs in Elderly Patients with Rheumatoid Arthritis.

Background and Objectives: Treatment for elderly (aged ≥75 years) patients with rheumatoid arthritis (RA) is important because they usually have several complications and organ dysfunction and are more susceptible to drug-related adverse events. Abatacept (ABT) treatment is relatively safe in elderly RA patients; however, the real-world data of efficacy and long-term retention of ABT is sparse in such patients. This study aimed to investigate the clinical efficacy and long-term retention rates of ABT in elderly Japanese RA patients. Materials and Methods: This 10-year retrospective observational cohort study was performed in two centers in Fukushima, Japan. We reviewed the clinical features of elderly RA patients who received ABT and investigated the differences in retention rates with concomitant administration of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Results: The clinical characteristics of younger (<75 years old, 39 cases) and elderly (≥75 years old, 20 cases) RA patients were generally similar. Although the efficacy was also similar, the concomitant administration of csDMARDs with ABT differed between the two groups. Younger patients significantly decreased methotrexate (MTX) administration than elderly patients (p < 0.01), and elderly patients significantly received tacrolimus (TAC) (p < 0.01) or salazosulfapyridine (SASP; p = 0.01) than younger patients. The overall retention and infection-free survival rates were similar between the two groups. Conclusion: Elderly RA patients showed sustained retention rates compared to younger RA patients. TAC and SASP can help to maintain sustained retention rates in elderly RA patients.