Advances in the therapy of idiopathic inflammatory myopathies

To review progress in areas pertinent to the development of better therapies for the idiopathic inflammatory myopathies.

New classification criteria for the idiopathic inflammatory myopathies have been proposed in an effort to define disease subsets with more uniform prognoses and responses to therapy. Diseases that may mimic the idiopathic inflammatory myopathies can be differentiated more accurately with molecular testing and biochemical and immunohistochemical analysis of muscle tissue. Advances in our understanding of the pathogenesis of the idiopathic inflammatory myopathies have served to identify potential new therapeutic targets. International collaborative study groups have reached consensus on outcome measures and on the optimal design of clinical trials in the idiopathic inflammatory myopathies. Tumor necrosis factor-alpha antagonists, rituximab, and the calcineurin inhibitors are being used to treat the idiopathic inflammatory myopathies, but their efficacy has not yet been tested in randomized clinical trials.

Future advances in the development of therapies for the idiopathic inflammatory myopathies have been enabled by recent progress in myositis classification, differential diagnosis, basic science, and clinical trial design. Preliminary studies suggest that calcineurin inhibitors, tumor necrosis factor antagonists, and rituximab may be effective treatments.