Benefit is significant for skin and muscle
Changes in the two major components of dermatomyositis were tracked individually. For skin symptoms, patients were evaluated with the Cutaneous Dermatomyositis Disease Areas and Severity Index (CDASI). For muscle involvement, symptoms were evaluated with the 8-item Manual Muscle Testing (MMT-8) tool.
“The effects of IVIg on the muscle and the skin were both highly statistically significant,” Dr. Aggarwal reported. He said the CDASI score was reduced by almost half at the end of 16 weeks among those treated with IVIg relative to those treated with placebo. Improvement in MMT-8 scores were also clinically as well as statistically significant.
The IVIg therapy was well tolerated. The most common adverse effects in this study, like those reported with IVIg when used to treat other diseases, were headache, pyrexia, and nausea, but Dr. Aggarwal reported that these were generally mild.
Serious adverse events, particularly thromboembolism, did occur over the course of the study, but the rate of events was only slightly higher in the group receiving active therapy (5.8% vs. 4.2%).
Patients who entered the study were permitted to remain on most immunosuppressive therapies, such as methotrexate, mycophenolate, tacrolimus, and glucocorticoids. Dr. Aggarwal said that the majority of patients were taking a glucocorticoid and at least one nonglucocorticoid immunosuppressant.
Effect on associated conditions is planned
The data from this trial have not yet been analyzed for the impact of IVIg on conditions that occur frequently in association with dermatomyositis, such as interstitial lung disease (ILD) and dysphagia, but Dr. Aggarwal reported that there are plans to do so. Although severe ILD was a trial exclusion, the presence of mild to moderate ILD and dysphagia were evaluated at baseline, so the impact of treatment can be assessed.
There are also plans to evaluate how the presence or absence of myositis-specific antibodies, which were also evaluated at baseline, affected response to IVIg.
Dr. Aggarwal has financial relationships with more than 15 pharmaceutical companies, including Octapharma, which provided financial support for this trial. Dr. Schulze-Koops reported no relevant potential conflicts of interest.