Leflunomide treatment in corticosteroid-dependent myasthenia gravis: an open-label pilot study.

Leflunomide is an effective drug used in the treatment of rheumatoid arthritis. Here we report the findings of an open-label pilot study, which found that leflunomide is also an effective treatment for myasthenia gravis (MG). This study recruited 15 corticosteroid-dependent MG patients. For 6 months, leflunomide 20 mg was given to these patients daily along with prednisone. The quantitative myasthenia gravis (QMG) scores and MG activities of daily living (MG-ADL) profiles were measured in these MG patients. After 6 months of treatment, 9 of the 15 patients enrolled in this study showed improvements in both QMG and MG-ADL. The mean QMG scores (13.4 to 8.5) and MG-ADL profiles (5.8 to 2.8) were significantly decreased (P = 0.01, 0.006 respectively). Furthermore, we found that the mean corticosteroid doses were reduced after treatment with leflunomide (24.3 to 12.3 mg per day). Leflunomide is a well-tolerated and efficacious treatment for corticosteroid-dependent MG, which may also enable lower doses of corticosteroids to be administered.