Efficacy and tolerability of subcutaneously administered methotrexate including dose escalation in long-term treatment of rheumatoid arthritis in a Japanese population

ABSTRACT Objectives The aim of this article is to evaluate the efficacy and safety of subcutaneously administered methotrexate (MTX) for Japanese patients with active rheumatoid arthritis. Methods MTX-naïve patients were randomized in a 1:1 ratio to receive a 12-week administration of either 7.5 mg MTX subcutaneously (MJK101, a prefilled syringe for subcutaneous injection) or 8 mg MTX orally in Part 1 of the trial. The primary end point was a 20% improvement in the American College of Rheumatology criteria (ACR20) at Week 12. In the second part, all enrolled patients received MJK101 weekly for 52 weeks with doses starting from 7.5 to 15 mg with 2.5 mg increments with the option of self-administration of MJK101. Results The efficacy of MJK101 was comparable to oral MTX following 12 weeks of treatment at the starting doses. A numerically higher ACR20 response rate and fewer adverse events in particular gastrointestinal adverse events were observed. During long-term subcutaneous treatment, MJK101 was well tolerated across all tested doses. Patients clinically improved upon dose escalation. Conclusions Subcutaneously applied MTX (MJK101) was efficient and well tolerated over a long-term treatment period in the Japanese population with doses up to 15 mg/week. Subcutaneous administration of MTX is a beneficial option for Japanese patients with rheumatoid arthritis.