The effectiveness and safety of subcutaneous methotrexate injection in Japanese patients with rheumatoid arthritis in a real-world setting

OBJECTIVES: To clarify the effectiveness and safety of subcutaneous injections (SC) of methotrexate (MTX) in Japanese patients with rheumatoid arthritis using real-world data. METHODS: In this retrospective observational study, 82 patients with rheumatoid arthritis were administered SC MTX at our department and affiliated facilities for 24 weeks after approval in September 2022. Drug continuation rate, disease activity, clinical symptoms including adverse events, and glucocorticoid dose after SC MTX administration were retrospectively examined. background: age 59.8 years, male/female 16/66, disease duration 8.6 years, stage I/II/III/IV 36/32/2/11, DAS28-ESR 3.5, Clinical Disease Activity Index 10.4, and Simplified Disease Activity Index 11.2. The SC MTX continuation rate after 24 weeks (primary endpoint) was 86.6%. In 72 of 82 patients (87.8%), oral MTX was switched to SC MTX. Mean oral MTX dose before the switch was 10.6 mg/week. The mean maximum dose after switching to SC was 12.0 mg/week. Adverse events were observed in 30 patients (36.6%), with a total Common Terminology Criteria for Adverse Events grade of 2 or lower. Clinical symptoms such as nausea, liver dysfunction, and stomatitis improved in 15 (20.8%) patients. In 53 patients who switched from oral to SC MTX, the disease activity scores were improved, and the glucocorticoid dose could be reduced. CONCLUSION: In real-world setting, switching from oral to SC MTX is useful in Japanese patients with rheumatoid arthritis.