Tysabri Washout Requirements When Switching Therapies

Switching FROM Tysabri to Another DMT

Disease rebound or reactivation is a significant concern when discontinuing Tysabri, particularly with prolonged washout periods 1

When switching TO Tysabri from immunosuppressive medications, the traditional recommendation is a washout period of four times the drug's terminal half-life to minimize immunosuppressive burden 2, 3
For biologic therapies specifically, clinical trials required discontinuation for at least 3 months prior to initiating new biologic therapies 2, 3
When switching from fingolimod to Tysabri, a washout period of four times fingolimod's terminal half-life is recommended to allow proper pretreatment assessments and minimize immunosuppressive burden 4

Ensure adequate clearance of prior immunosuppressants (4× terminal half-life) when initiating Tysabri 2, 3
For prior biologic therapy, consider 3-month washout when initiating Tysabri 2, 3
Complete pretreatment assessments including JCV antibody status before starting Tysabri 5, 1

Overlapping immunosuppressive therapies should be avoided when switching between biologics due to increased infection risk 2, 3