Generation-Dependent Retention Rates and Reasons for Discontinuation of Molecular Targeted Therapies in Patients with Rheumatoid Arthritis: From FIRST Registry

INTRODUCTION: The study aimed to optimize medical care for elderly patients with rheumatoid arthritis (RA) by examining the 3-year continuation rate of different molecular targeted therapies across age groups in Japan, which has a significant elderly population. METHODS: The study included patients with RA who started molecular targeted therapies between 2013 and 2019 and divided them into three age groups. The primary outcome was to assess the 3-year continuation rate of each drug and analyze reasons for treatment discontinuation using inverse probability of treatment weighting. RESULTS: Among 2292 patients analyzed, tumor necrosis factor (TNF) inhibitors were most commonly used in those younger than 65 years of age (43.5%), while Janus kinase (JAK) inhibitors were also utilized (17.1%). In contrast, JAK inhibitors were less frequently used in patients aged 75 years and older (7.8%), with cytotoxic T lymphocyte antigen 4 immunoglobulin fusion proteins (CTLA4-Ig) being the most common (39.2%). JAK inhibitors and anti-interleukin-6 receptor (IL-6R) antibodies had higher continuation rates than other drugs in patients under 65 years (p < 0.001). For those aged 65–74 years, JAK inhibitors and CTLA4-Ig had higher continuation rates (p < 0.001), while among those aged 75 years and older, CTLA4-Ig and IL-6R antibodies had higher continuation rates (p < 0.001). Inadequate efficacy was the main reason for discontinuation in all age groups, while infection leading to discontinuation increased with age. CONCLUSIONS: The study highlights the need to consider different age groups separately in elderly RA care. Among patients aged 75 years and older, abatacept and anti-IL-6R antibodies showed the highest continuation rates, suggesting their potential suitability and efficacy for this specific age cohort. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40744-023-00603-8.