Anifrolumab in Refractory Juvenile Dermatomyositis.

Juvenile dermatomyositis (JDM) is a rare, idiopathic inflammatory myopathy of childhood and first-line therapy typically includes corticosteroids and immunosuppressive agents, but complete and sustained remission of the disease is not always achieved. This case report describes an 8-year-old girl with refractory JDM who failed multiple therapies, including corticosteroids, disease-modifying agents, and JAK inhibitors. After the introduction of anifrolumab, a monoclonal antibody targeting the type I interferon receptor, the patient experienced significant improvement in both skin and muscle symptoms. Her disease activity scores decreased markedly, and the response was sustained over six months with no adverse effects. This is the third reported case of JDM treated with anifrolumab, highlighting the potential of targeting the type 1 interferon pathway as a promising therapeutic strategy for patients with refractory disease. The case underscores the importance of IFN-I dysregulation in dermatomyositis and the value of blocking this pathway in difficult-to-treat cases.