New developments in the treatment of certain refractory inflammatory myositis

German clinicians report a case of antisynthetase syndrome (ASyS) treated with several biotherapies:

• the patient, aged 45, had ASyS with signs of joint, muscle (myositis) and respiratory (interstitial lung disease) disease, with the presence of autoantibodies directed against the Jo-1 antigen,
• an initial treatment with CAR-T cells directed against CD19 lymphocytesC’est une catégorie de globules blancs. Ces petites cellules au noyau arrondi et volumineux sont impliquées dans les aspects spécifiques des réactions immunitaires. Il existe deux catégories de lymphocytes les lymphocytes B (qui secrètent les anticorps) et les lymphocytes T. resulted in remission for 9 months,
• following a relapse, The patient then received the same cell therapy, this time with a non-response to the treatment.
• after a wait-and-see treatment with anti-CD38 (daratumumab), the patient was able to receive a new type of CART-T cell called BCMA on a compassionate basis, this time with a favourable and lasting response.

This case illustrates the challenges of reinjecting CART-T cells, but also the progress made by innovative biotherapies in refractory forms of autoimmune diseases.

BCMA CAR T cells in a patient with relapsing idiopathic inflammatory myositis after initial and repeat therapy with CD19 CAR T cells. Müller F, Wirsching A, Hagen M, et al. Nat Med. 2025 Apr