IFNA1 and myeloid sarcoma: From the 50 patients who stopped GA, all patients with previous IFN exposure escalated therapy to second line drugs, while those in the treatment-naive group followed a variety of pathways, including switching to second-line drugs (60.4 % patients), but also to IFN (29.2 %) and immunosuppressive drugs (4.2 %), as well as stopping treatment altogether following patients’ demands (4.2 %) or conversion to secondary progressive MS (2.1 %).