To investigate the feasibility, safety and clinical response to combine Rituximab and plasma exchange (PLEX) as induction therapy for patients with seropositive generalized myasthenia gravis (MG).

In this single-centre, open-label study patients with moderate-severe symptoms new-onset or exacerbated MG were recruited. Rituximab was administered before and after 6 PLEX sessions and intravenous immunoglobulin replacement doses every two PLEX. PLEX were performed through peripheral venous access with ultrasound guidance when needed. Tolerability and clinical severity were assessed by MGFA classification, MG-ADL score and documenting concomitant medications at baseline and after 6 months.  

Between December 2022-October 2025, we included 13 patients; 7 (54%) were women with median age of 65 years (IQR: 51-78). All patients had positive AChR-antibodies, and one had concurrent MuSK. At baseline, 1 patient was in MGFA class V, 6 in IV, 4 III and 2 IIb; all received pyridostigmine, 12 prednisone (median dose 30 mg/d; IQR 19-45), 4 azathioprine and 1 mycophenolate. Five (40%) patients were treated at onset-MG (median MG-ADL=8; IQR: 5-13) and 8 (60%) for predominantly bulbar exacerbations (MG-ADL=6.5; IQR: 5-8).

Only mild adverse effects were observed in 3 (23%) patients. Therapy was extended for 11 (85%) patients, in 7 (64%) with 6 additional PLEX sessions over 2 months and in 4 (36%) with maintenance monthly PLEX sessions. At 6 months, 8 of 10 evaluated patients (80%) showed clinically meaningful improvement (MG-ADL=2.5; IQR: 1-5) with decreased dose of prednisone (median dose 20 mg/d; IQR: 12-38), and 2 (20%) did not respond (MG-ADL=6.5;IQR 5-8) and were switched to C5-inhibitor therapy.  

In our patients, the antibody- and B cell-depleting combinational was feasible, safe and efficacious as induction therapy, showing a favourable 6-month response in most cases.