An approach to natalizumab hypersensitivity: a case series of induction of tolerance.

Induction of tolerance protocols have been applied successfully to manage allergic reactions to many medications. Hypersensitivity reactions to natalizumab (TYSABRI®) have been recognized as a growing problem. In circumstances where a hypersensitivity reaction to a medication has occurred, but no suitable alternative exists, drug induction of tolerance protocols may be considered. Drug induction of tolerance protocols were performed in three patients with prior hypersensitivity reactions to natalizumab. All three patients tolerated the protocol without adverse reactions, allowing for the safe reintroduction of natalizumab. To conclude, this case series demonstrates success with an induction of tolerance procedure to a highly effective biological agent for multiple sclerosis, in patients with allergic reactions to natalizumab.