The first case concerns a 27-year-old man in Canada with autoimmune necrotizing myopathy with anti-PRS:
- after 8 months of conventional treatment (glucocorticoids, methotraxate, IV immunoglobulins, rituximab) with no effect and 6 months in intensive care unit,
- the initiation of daratumumab (16mg/kg/week) led to a clear improvement in four weeks, with discharge from the intensive care unit at the 11th month.
The second patient in Germany, aged 19 years, with rapidly progressive interstitial lung disease associated with dermatomyositis with anti-MDA5 :
- was treated for four months (glucocorticoids, IV immunoglobulins, tofacitinib, cyclophosphamide, mofetil mycophenolate, rituximab) without success,
- treatment with daramutumab (1800mg/week subcutaneously) for four weeks led to withdrawal of oxygen therapy and reduction of the daily dose of prednisolone, with stable remission at six months.
