High efficacy of rituximab for myasthenia gravis: a comprehensive nationwide study in Austria.

Abstract

BACKGROUND:

Most patients with myasthenia gravis (MG) need long-term immunosuppressive therapy. However, conventional agents may have intolerable side effects, take too long or fail to achieve disease control. Rituximab (RTX) has emerged as an off-label treatment for refractory MG, but data on its use are still sparse.

METHODS:

We conducted a retrospective nationwide study contacting all Austrian neurologists to provide anonymized data of all adult MG patients treated with RTX and minimum follow-up of 3 months. The Myasthenia Gravis Foundation of America Postintervention Status scale was used to assess outcomes.

RESULTS:

34 (60.7%) of a total of 56 patients were women. Median (IQR) age at diagnosis of MG and start of RTX were 41.5 (24.3; 65.8) and 47.5 (33; 71) years, respectively. Antibodies (ab) against acetylcholine receptor (AchR) and muscle-specific tyrosine kinase (MuSK) were present in 69.6% and 25% of patients, respectively (seronegative: 5.4%). Before RTX, 47 (83.9%) patients had had plasma exchange, immune adsorption or immunoglobulins. Three months after RTX, 14 of 53 (26.4%) patients were in remission. At last follow-up after a median of 20 (10; 53) months, remission was present in 42.9% of patients and another 25% had minimal manifestations. Remission was more frequent in patients with MuSK ab vs. those with AchR ab (71.4% vs. 35.9%, p = 0.022). RTX was safe. The presence of MuSK ab independently predicted remission after RTX.

CONCLUSION:

In this retrospective study on RTX for MG, the largest to date, RTX appeared safe, efficacious and fast acting. Benefit from RTX was greatest in MuSK ab + MG.

• Authors: Raffi Topakian, Fritz Zimprich, Stephan Iglseder, Norbert Embacher, Michael Guger, Karl Stieglbauer, Dieter Langenscheidt, Jakob Rath, Stefan Quasthoff, Philipp Simschitz, Julia Wanschitz, David Windisch, Petra Müller, Dierk Oel, Günther Schustereder, Stefan Einsiedler, Christian Eggers, Wolfgang Löscher
• Journal: Journal of neurology (J Neurol) Vol. 266 Issue 3 Pg. 699-706 (Mar 2019) ISSN: 1432-1459 [Electronic] Germany
• PMID: 30649616 (Publication Type: Journal Article)

Chemical References

• Immunologic Factors
• Receptors, Cholinergic
• Rituximab
• MUSK protein, human
• Receptor Protein-Tyrosine Kinases

Topics

• Adult
• Aged
• Austria
• Cohort Studies
• Dose-Response Relationship, Drug
• Female
• Humans
• Immunologic Factors (therapeutic use)
• Logistic Models
• Male
• Middle Aged
• Myasthenia Gravis (drug therapy)
• Receptor Protein-Tyrosine Kinases (immunology)
• Receptors, Cholinergic (immunology)
• Rituximab (therapeutic use)
• Treatment Outcome