, according to a statement from manufacturer Octapharma USA.
Dermatomyositis is a rare, idiopathic autoimmune disorder that affects approximately 10 out of every million people in the United States, mainly adults in their late 40s to early 60s, according to the company, but children aged 5-15 years can be affected. The disease is characterized by skin rashes, chronic muscle inflammation, progressive muscle weakness, and risk for mortality that is three times higher than for the general population.
There are no previously approved treatments for dermatomyositis prior to Octagam 10%, which also is indicated for chronic immune thrombocytopenic purpura in adults.
The approval for dermatomyositis was based on the results of a phase 3 randomized, double-blind, placebo-controlled clinical trial (the ProDERM trial) that included 95 adult patients at 36 sites worldwide, with 17 sites in the United States. In the trial, 78.7% of patients with dermatomyositis who were randomized to receive 2 g/kg of Octagam 10% every 4 weeks showed response at 16 weeks, compared with 43.8% of patients who received placebo. Response was based on the 2016 American College of Rheumatology/European Alliance of Associations for Rheumatology myositis response criteria. Placebo patients who switched to intravenous immunoglobulin (IVIG) during a trial extension had response rates at week 40 similar to the original patients at week 16.
“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,” Rohit Aggarwal, MD, medical director of the Arthritis and Autoimmunity Center at the University of Pittsburgh and a member of the ProDERM study Steering Committee, said in the Octapharma statement.
Safety and tolerability were similar to profiles seen with other IVIG medications, according to the statement. The medication does carry a boxed warning from its chronic ITP approval, cautioning about the potential for thrombosis, renal dysfunction, and acute renal failure.
The most common adverse reactions reported by dermatomyositis patients in the ProDERM trial were headache, fever, nausea, vomiting, increased blood pressure, chills, musculoskeletal pain, increased heart rate, dyspnea, and reactions at the infusion sites.
Read the full prescribing information here.