Eisai and Toyama's iguratimod, and Astellas' Gonax OKed in Japan

Japanese drug major Eisai (TYO: 4523) and Toyama Chemical have received approval from Japan's Ministry of Health, Labor and Welfare to market iguratimod (development code: T-614) for the treatment of rheumatoid arthritis.

Iguratimod, originally discovered by Toyama Chemical, which is owned by Fujifilm, is a novel disease modifying anti-rheumatic drug (DMARD) jointly developed in Japan by the companies based on a co-development and license agreement previously concluded between them.

In a clinical study of iguratimod administered as a monotherapy in patients with rheumatoid arthritis, the agent demonstrated superiority over placebo and non-inferiority compared to an existing DMARD (salazosulfapyridine). In addition, in a trial of iguratimod in combination with methotrexate (MTX), the standard of care, conducted in rheumatoid arthritis patients who did not achieve satisfactory benefit with MTX alone, patients who were administered a combination of the two agents demonstrated favorable tolerability as well as significant improvements compared to those treated with placebo (MTX-only arm) in the study's primary endpoint of ACR20 response rate at Week 24. Out of all the orally-administered anti-rheumatic drugs currently approved in Japan, iguratimod is the first agent evaluated in domestic clinical trials to demonstrate efficacy as an add-on therapy to MTX in patients who did not achieve satisfactory benefit with MTX alone.