The combination of leflunomide (LEF) and methotrexate (MTX) in patients with rheumatoid arthritis (RA) who are failing on MTX treatment alone: A double-blind placebo (PLC) controlled study. - Kremer,J.M.; Caldwell,J.R.; Cannon,G.W.; Genovese,M.; Cush,J.J.; Bathon,J.; Coleman,J.C. (Arthritis Rheum, 2000)