Intravenous immunoglobulin (IVIG) plus ciclosporin reduced the incidence of coronary artery abnormalities compared with IVIG alone (95% CI 0.25–0.86; P = 0.010) in a phase III study of 173 children with Kawasaki disease who were predicted to be unlikely to respond to IVIG therapy. Responsiveness to IVIG therapy was predicted on the basis of a composite risk score and individuals with pre-existing coronary artery abnormalities were excluded from the study. IVIG plus ciclosporin was safe and effective at 12 weeks, and no differences in adverse events were reported between treatment groups.