The methotrexate scored tablet, Metolate® tablet 2 mg (MTL), was developed for use by patients with rheumatoid arthritis (RA) in Japan as a generic drug of the methotrexate capsule, Rheumatrex® capsule 2 mg.Because it is a generic drug, MTL has no clinical evidence for RA patients. We therefore conducted a post-marketing observational study of MTL in patients with RA in order to collect clinical data concerning the safety and efficacy of the drug. As a result, the incidence of adverse drug reactions (ADR) was 16.2% (50/308) and major ADR included hepatic and gastrointestinal disorders. In terms of the efficacy judged by investigators, 62.6% (184/294) of the patients showed a positive response (29.9% marked improvement, 32.7% moderate improvement). The efficacy rate of DAS28 (3)-CRP and DAS28 (3)-ESR based on the EULAR response criteria was 65.9% (147/223) and 60.2% (77/128) respectively. On the other hand, the original drug was reported to have an ADR rate of 18.62% (715/3,839), major ADR included hepatic and gastrointestinal disorders, and the efficacy rate judged by investigators was 47.2% (1,090/2,310). In conclusion, this study revealed that MTL has similar safety and efficacy profiles to the original drug in indirect comparison with the results of the original drug’s post-marketing observational study. In addition, we have found that MTL may contribute to RA treatment by adjusting an optimum dosage in1mg units.
