The reference treatment for relapsing-remitting multiple sclerosis which progresses in flare-ups is interferon beta injection, for lack of anything better.

In 2007, in severe multiple sclerosis when interferon beta does not seem to be effective enough, the harm-benefit balance of natalizumab (Tysabri°) was unfavourable since there was too little evidence of its efficacy in the face of a fatal risk of progressive multifocal leukoencephalopathy  (brain infection). By the end of 2014, natalizumab’s efficacy as a monotherapy still had not been demonstrated. Post-market evidence confirms the adverse effects highlighted in the clinical trials: even more frequent cases of progressive multifocal leukoencephalopathy than originally estimated, and sometimes severe hypersensitivity reactions. The risk of long-term cancers cannot be ruled out.

Alemtuzumab (Lemtrada°) has been authorised in the European Union in this same clinical situation. Its evaluation is too biased to be able to judge its potential usefulness. Its adverse effects profile, already known in oncology, has been confirmed: sometimes severe reactions associated with the infusion, risks of infection and of cancer associated with severe, prolonged immune deficiency, and other particularly frequent immune disorders (thyroid disorders, purpura, etc.).

In practice, however severe the multiple sclerosis, it is unreasonable to expose patients to the many adverse effects of natalizumab and  alemtuzumab for such dubious benefits.

©Prescrire 1 March 2015

"Natalizumab (Tysabri°) and multiple sclerosis" Prescrire Int 2015; 24 (158): 65-67. (Pdf, subscribers only).

"Alemtuzumab (Lemtrada°) and multiple sclerosis" Prescrire Int 2015; 24 (158): 69. (Pdf, subscribers only).