Myositis Management: Clinical Trials Provide New Insights into Treatment Options

After citing a 1993 study evaluating high-dose, intravenous immunoglobulin (IVIG) infusions to treat dermatomyositis,¹⁰ Dr. Chenoy summarized the ProDERM study, a prospective, double-blind, randomized, placebo-controlled phase 3 study evaluating the efficacy, safety and long-term tolerability of IVIG in patients with dermatomyositis. This study is important because IVIG has been used off-label to treat dermatomyositis, but to date has not been proven efficacious in a large, randomized controlled trial.

In the ProDERM study, adult patients with dermatomyositis on a stable dose of standard therapy (i.e., mycophenolate mofetil, methotrexate, glucocorticoids or hydroxychloroquine) were randomized 1:1 to receive either 2 g/kg of IVIG or placebo every four weeks for 16 weeks. Patients who showed clinical deterioration in this period were switched to the alternate treatment. At week 16, all patients on placebo and those without clinical deterioration on IVIG received 2 g/kg of IVIG every four weeks for 24 weeks. The primary efficacy endpoint was the proportion of responders in each group with at least minimal improvement in the total improvement score (a composite response criteria) without deterioration at two consecutive visits up to week 16.¹¹ The primary endpoint was met in 79% of patients receiving IVIG and 44% of patients receiving placebo. In terms of safety, treatment-emergent adverse events were comparable in the IVIG and placebo groups.¹¹ This study confirmed the efficacy, safety and tolerability of IVIG treatment in adult patients with dermatomyositis.

In Sum

As Dr. Chenoy clearly outlined, this is an exciting time in myositis research, and much will be learned in the coming years regarding how to best treat patients with these diseases.

Jason Liebowitz, MD, completed his fellowship in rheumatology at Johns Hopkins University, Baltimore, where he also earned his medical degree. He is currently in practice with Skylands Medical Group, N.J.

References

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