Drug Retention Rates and the Safety of Janus Kinase Inhibitors in Elderly Patients with Rheumatoid Arthritis

Background: We examined the real-world drug retention rate and safety data of Janus kinase inhibitors (JAKis) in elderly patients with rheumatoid arthritis (RA).

Methods: This study enrolled 133 RA patients (≥65 years) with sufficient clinical data who were initiated with JAKis during the study period. These patients were divided into two groups: the very elderly group (≥ 75 years) and the elderly group (65 ≤ years < 75). The drug retention rates of JAKis were compared using Kaplan-Meier curves.

Results: The discontinuation rates of JAKis were as follows: lack of effectiveness 27 (20.3%), adverse events (AEs) 29 (21.8%), and remission 2 (1.5%). There was no significant difference in the overall drug retention rate between the very elderly group (≥75 years) and the elderly group. Furthermore, the overall drug retention rates of JAKis were not affected by gender, methotrexate use, and anti-citrullinated protein/peptide antibody (ACPA) status. The discontinuation rates of JAKis due to AEs were comparable both in the very elderly group (≥75 years) and the elderly group (65 ≤ years < 75). Whereas chronic lung disease and hypoalbuminemia were independently associated with discontinuation rates due to AEs, the overall drug retention rates were significantly lower in patients treated with the approved dose of JAKis than in those treated with a reduced or tapered dose.

Conclusions: Our results suggest that the overall drug retention rate of JAKis in very elderly patients (≥75 years) was comparable with that in elderly patients (65 ≤ years < 75). The discontinuation rates of JAKis due to AEs were also comparable both in very elderly group patients and elderly patients.