FDA Approves IVIG for Dermatomyositis

The FDA approved intravenous immunoglobulins (IVIG; Octagam 10%) for treating adults with dermatomyositis, a rare chronic autoimmune disease, drugmaker Octapharma announced on Tuesday.

Support for the indication was based on findings from ProDERM, a phase III placebo-controlled trial of 95 adults with dermatomyositis. Responses with IVIG treatment (2 g/kg) every 4 weeks more than doubled by week 16 compared with placebo (78.7% vs 43.8%, respectively; P=0.0008), as measured by the 2016 American College of Rheumatology/European League Against Rheumatism myositis response criteria.

“The ProDERM study will have a significant impact on clinical practice because IVIG is likely to become an important treatment option for patients with dermatomyositis,” study investigator Rohit Aggarwal, MD, MS, of the University of Pittsburgh School of Medicine, said in a statement. “The study gives clinicians much more confidence in the efficacy and safety of intravenous immunoglobulin and provides valuable information about what type of patient is best suited for the treatment.”

All patients in the study had active disease, with symmetrical proximal muscle weakness and skin rash, and were either on or had failed standard immunosuppressive therapy. Secondary endpoints — Cutaneous Dermatomyositis Disease Area and Severity Index, all components of Total Improvement Score other than muscle enzyme — significantly favored the IVIG treatment arm.

After placebo patients switched to IVIG during an extension phase, response rates increased to 69.6% by week 40, which were similar to those who started and remained on active treatment throughout (71.1%).

Dermatomyositis affects roughly one in every 100,000 people in the U.S., and patients have a threefold higher risk of mortality versus the general population. The disease is characterized by skin rashes, chronic muscle inflammation, and progressive muscle weakness. Complications of dermatomyositis can include dysphagia, aspiration pneumonia, and breathing problems, as well as calcium deposits on connective tissue, muscles, and skin. Onset typically occurs in later life, but the illness can also occur in children.

Safety and tolerability of IVIG in ProDERM was consistent with previous experience, and common adverse events (>5%) were chills, dyspnea, fever, headache, increased blood pressure and heart rate, infusion site reactions, musculoskeletal pain, and nausea or vomiting, according to the FDA label. Boxed warnings include the risk for thrombosis, renal dysfunction, and acute renal failure.

Octagam 10% is also approved for treating chronic immune thrombocytopenic purpura in adults.