Rapidly increasing off-label use of rituximab in multiple sclerosis in Sweden - Outlier or predecessor?

Abstract

Objectives: Off-label use of rituximab to treat MS patients in Sweden is high, and the need for long-term safety data may not be met. Our objectives were to assess the rate of rituximab prescription in patients with multiple sclerosis in Sweden and, in addition, to evaluate the safety of rituximab in a single centre for patients with multiple sclerosis.

Material and methods: Review of the Swedish MS register was performed to study the number of MS patients treated with rituximab during the last 6 years. Investigation also included a retrospective review of medical files in search for possible side effects/adverse events in all adult patients with MS treated with rituximab at Uppsala University Hospital.

Results: Presently, in Sweden the rate of rituximab prescriptions in relation to other annually started of disease- modifying drugs in MS is 53.5%.

Conclusions: The share of MS patients in Sweden who are treated with rituximab is very high, and also rapidly increasing. Taken into account the off-label use, cases with adverse medical conditions that could possibly be related to rituximab use should be reported thoroughly.

Keywords: adverse events; immunomodulatory drugs; multiple sclerosis; off-label prescription; pharmacotherapy; rituximab side effects.