The results of the FORCE trial evaluating the effects of rituximab in refractory myasthenia gravis have been published.
The FORCE trial
The FORCE trial is a Phase II pilot trial coordinated by Prof. O. Benveniste (Inflammatory Myopathies & Targeted Innovative Therapies, Myology Research Center) and supported by the AFM-Téléthon. The objective was to evaluate the effects of rituximab over 12 months in generalised myasthenia with autoantibodies to acetylcholine receptors (12 participants) and myositis with anti-synthetase autoantibodies (12 participants), refractory to traditional treatments.
Rituximab is a drug that reduces the amount of B-lymphocytes (and thus the production of auto-antibodies), already used in the treatment of certain cancers and autoimmune diseases.
A tendency to improve muscle function
After the publication of the FORCE results in myositis with anti-synthetase autoantibodies, the results for participants with refractory generalised myasthenia gravis were published in the Journal of Neuromuscular Diseases.
Of the 12 participants, 11 (8 women and 3 men) completed the study. At the time of inclusion, the average age was 44 years and the average duration of illness was 13 years. Before participating in the study, all were treated for an average of 12 years (four immunomodulatory treatments on average) and a thymectomy was performed in eight participants.
Only one participant reached the primary endpoint of the trial (improvement of at least 20 points in muscle function at 12 months based on myasthenic muscle score). Two participants showed an increase of at least 18 points at 12 months. Clinical improvement was not associated with a reduction in immunosuppressive therapy. A beneficial effect of rituximab on muscle function was however observed in half of the patients at 12 months and persisted in one third of patients at 18 months.
However, other longer-term trials with more participants will be needed to better evaluate the effects of rituximab in refractory generalised myasthenia gravis with autoantibodies to acetylcholine receptors.
Sur Clinicaltrial.gov : NCT00774462
