Iguratimod for the treatment of rheumatoid arthritis in Japan.

Iguratimod (IGU), a small-molecule compound, was developed as a disease-modifying antirheumatic drug in Japan. The pharmacological studies showed that inhibition of the production of cytokines and immunoglobulins mainly contributes to its improvement effect on animal arthritis models. The first clinical study of IGU in Japanese patients with rheumatoid arthritis was started in 1992 and Phase III studies were started in 1998.

Safety and efficacy of combination therapy of iguratimod with methotrexate for patients with active rheumatoid arthritis with an inadequate response to methotrexate: an open-label extension of a randomized, double-blind, placebo-controlled trial.

Objective: To obtain safety and efficacy data on combination treatment with iguratimod and methotrexate (MTX) in an open-label extension study in patients with active rheumatoid arthritis (RA).

Methods: Following a 28-week, randomized, double-blind trial of adding iguratimod or placebo to stable MTX therapy, patients entered a 24-week extension. Patients randomized to the iguratimod + MTX group continued treatment.

Concomitant iguratimod therapy in patients with active rheumatoid arthritis despite stable doses of methotrexate: a randomized, double-blind, placebo-controlled trial.

Objectives: To investigate the efficacy and safety of iguratimod (T-614) in Japanese patients with active rheumatoid arthritis who had inadequate response to stable background methotrexate (MTX) alone.

Methods: In this multicenter, double-blind, controlled trial, a total of 253 patients were randomized at 2:1 ratio to either the iguratimod group or the placebo group. Iguratimod was orally administered at dosages of 25 mg/day for the first 4 weeks (25 mg once daily) and 50 mg/day for the subsequent 20 weeks (25 mg twice daily).