Exploring rituximab for the treatment of refractory myasthenia gravis: a single-centre experience

Myasthenia gravis (MG) is a rare autoimmune disorder that affects neuromuscular transmission, leading to muscle weakness. While most patients respond to standard treatments, approximately 15% remain refractory, prompting interest in alternative therapies. This study examined the use of rituximab in patients with refractory MG at a single centre in Latvia, intending to broaden discussions on treatment strategies.

The prospective cohort study was conducted at Pauls Stradiņš Clinical University Hospital from November 2022 to March 2024. Refractory MG was defined as failure to achieve adequate disease control despite standard immunosuppressive therapy, including patients with persistent symptoms, recurrent crises or intolerance to medications. Myasthenia Gravis Composite Score (MGCS), Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life (scores at baseline and monthly for 6 months) were completed. Glucocorticosteroid doses were also recorded. Data were analysed using descriptive statistics and Wilcoxon signed-rank test, considering p<0.05 significant.

98 patients with MG were evaluated to identify treatment-refractory cases. A total of nine patients with refractory MG (median disease duration 7 years, range 1-12) were included and received a single low dose of rituximab. Among the nine patients treated, seven were acetylcholine receptor-positive and two were muscle-specific kinase antibody-seropositive. 6 months after treatment, the median MGCS decreased from 11.5 (IQR 7.3-17.8) to 7.5 (IQR 3.8-8.0) (p=0.025). The median daily corticosteroid dose decreased from 15.0 mg (IQR 10.0-20.9) to 8.5 mg (IQR 5.0-12.5) (p=0.036). There were no exacerbations of MG or significant adverse reactions.

Our findings suggest that rituximab may be a promising treatment option for refractory MG. The notable clinical benefits and safety profile make rituximab a valuable addition to this challenging autoimmune disorder treatment options. Further research is needed to refine patient selection and dosing for optimal treatment outcomes.