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Background: Treatment of anti-synthetase syndrome (ASyS) presents a clinical challenge: muscle involvement can lead to permanent disability and severe internal organ involvement is often life-threatening.
Case presentation: We present three patients with multidrug-resistant severe ASyS, who have been treated with blinatumomab by compassionate use. The 1 st patient, 67-year-old female, had reoccurring flares of myositis, new onset ILD and active myocarditis. The 2 nd patient, 36-year-old male, suffered from severe, progressive ILD, and myocarditis. The 3 rd patient, 47-year-old male, had debilitating myositis. All patients were anti-Jo1 antibody positive and were not responding to multiple immunosuppressive therapies including prednisone, immunoglobulins, rituximab. Blinatumomab induced complete depletion of CD19 + B cells in circulation and muscle tissue, a major decrease in anti-Jo1 autoantibody titers, without decreases in vaccination titers. Blinatumomab induced glucocorticoid-free remission of myositis with normalization of serum muscle enzymes and improvement of muscle strength in all patients. The 1 st patient entered clinical remission, with normalized CK levels, gain in muscle strength (MMT8 score 72 vs. 59) and improved 6-minute walking test (MWT 344 vs. 200m). Her (hsTropT) levels decreased (183 vs. 423ng/L). The dyspnea resolved (NYHA I vs. NYHA III), her FVC increased from 65% at baseline to 78% after 3 months. His mechanic hands resolved. The 2 nd patient demonstrated progressive clinical improvement with normalization of CK and CRP, an increase of the MMT8 score (80 vs. 70), improvement of 6MWT (398m, while baseline 6MWT could not be performed due to intense dyspnea). MRI revealed resolution of myositis. His hsTropT levels decreased (30 vs. 240ng/L). The progressive decline in FVC was halted (42 vs. 38% at baseline), DLCO increased (38 vs. 27%) and dyspnea improved from NYHA IV to NYHA II. HRCT showed a reduction in ground glass opacity after 3 months. The 3 rd patient showed a normalized CK and significant reduction in hsTropT (107 vs. 258ng/L) after 8 weeks. His 6MWT mobility increased (650 vs. 440m). We performed muscle biopsies before and after blinatumomab, showing depletion of CD19 or CD20 positive B-cells in the tissue after treatment, as well as reductions of necrotic muscle fibers with beginning regeneration. Adverse events included CRS grade 3, though with fast recovery, and one respiratory infection in the 2 nd patient. No ICANS occurred.
Learning points for clinical practice: This is the first report on treatment of patients with severe, treatment-refractory ASyS with blinatumomab. Treatment with blinatumomab induced rapid, glucocorticoid-free remission of myositis in all patients and improvement of all other manifestations. Blinatumomab may thus offer potential for induction of remission in treatment-refractory ASyS patients.
REFERENCES: NIL.
Acknowledgements: NIL.
Disclosure of Interests: Christina Duesing: None declared, Ayla Stütz: None declared, Andrea-Hermina Györfi BoeringerIngelheim, AbbVie, BoeringerIngelheim, Laura-Marie Lahu: None declared, Franca Sophie Deicher: None declared, Gamal Chehab: None declared, Jutta G. Richter: None declared, Marie Celine van Saan: None declared, Bilgesu Safak Tuemerdem: None declared, Alexandru-Emil Matei: None declared, Björn Buehring: None declared, Ricardo Grieshaber-Bouyer: None declared, Melanie Hagen BMS, Lilly, AlfaSigma, UCB, Biotest, BMS, Lilly, AlfaSigma, UCB, Biotest, Georg Schett BMS, Cabaletta, Janssen, Kyverna, Miltenyi, Novartis, Wolfgang Merkt Kyverna, Hexal-Sandoz, Novartis, Roche, Lilly, Boehringer-Ingelheim, Lilly, Galapagos, Evotec/BMS, Jörg Distler: None declared.
© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (