Study

A Multicenter, Parallel-group, Double-blind, 2-Arm, Phase III Study to Investigate the Efficacy and Safety of Anifrolumab Administered as Subcutaneous Injection and Added to Standard of Care Compared with Placebo Added to Standard of Care in Adult Participants with Idiopathic Inflammatory Myopathies (Polymyositis and Dermatomyositis)

This study is being done to learn more about anifrolumab in patients with idiopathic inflammatory myopathies (IIM), which includes disease subtypes of polymyositis (PM) and dermatomyositis (DM) and also to better understand the studied disease and associated health problems.

Why this Research Matters

This study is 122 weeks long. It includes a screening period of upto 6 weeks, a treatment period of 104 weeks and a follow up period of 12 weeks.

Who can Participate

Adult

Adults who are 18 years to 75 years old. Body weight of 40 kg to less than 100 kg at screening. Must have probable or definite diagnosis of PM or DM. 1. Must have moderate to severe PM or DM at screening measured by having MMT-9 score. 2. Currently receiving at least one of the following- a. oral prednisone b. Not more than one of the medications administered for a minimum of 12 weeks prior to screening and a stable dose for a minimum of 8 weeks; azathioprine, mycophenolate mofetil or mycophenolic acid, methotrexate, mizoribine, tacrolimus 3. Sexually active female with an intact cervix must have documentation of a cervical cancer screening. 4. All fertile males who are sexually active must use a condom from day 1 until at least 16 weeks after the final dose of study drug. 5. Participants with documented IBM, IMNM, juvenile myositis, drug induced PM or DM, cancer-associated PM or DM, amyopathic DM, and non-inflammatory myopathies are excluded. Other inclusions and exclusions apply.