Case reportBeneficial effect of tocilizumab in myasthenia gravis refractory to rituximab

- Tocilizumab is an anti-interleukin-6-receptor humanized monoclonal antibody.
- Tocilizumab was effective in two patients with refractory myasthenia gravis.
- The treatment was well tolerated without reported adverse events.
- Tocilizumab may represent a treatment option in refractory myasthenia gravis.

Muscle fatigue associated with myasthenia gravis is caused by autoantibodies interfering with neuromuscular transmission. Immunomodulating treatment is widely used in moderate to severe myasthenia, although the use of newer biological drugs except rituximab is rare. We describe the effect of tocilizumab, a blocker of interleukin-6 signalling, in two female myasthenia patients with high titres of serum acetylcholine receptor antibodies and insufficient response to rituximab. The first patient had been treated with high dose immunoglobulins regularly for several years and the second patient had been treated both with different oral immune suppressants and immunoglobulins before testing a low dose of rituximab without significant clinical effect. Subsequent treatment with tocilizumab resulted in clinical improvement within a few months. The first patient was switched back to rituximab, which resulted in worsening until tocilizumab was restarted. Tocilizumab can be a therapeutic option in cases not responding to rituximab.