Question: Do women, or what proportion of women, that discontinue Tysabri because (and only when) they become pregnant, experience rebound relapse during pregnancy. Thank you!

Discontinuation of Tysabri therapy after more than a year of treatment is associated with an increased risk of relapse, typically 4 to 8 months after the last infusion. In some cases these relapses are quite widespread and severe. Patients with active disease before starting treatment with Tysabri, usually defined as recent relapses and multiple enhancing lesions on MRI prior to starting Tysabri , have the highest risk of relapse after stopping Tysabri therapy, even if Tysabri was completely effective at shutting down all evidence of active disease.

The most common reason for stopping Tysabri in these circumstances is the desire to get pregnant or concern about developing PML (Progressive Multifocal Leukoencephalopathy)  with continued treatment. Normally, pregnancy is partially protective in MS patents during the 2nd and 3rd trimester but there are increasing reports of patients stopping tysarbi and experiencing severe relapses even during the 2nd and 3rd trimester.  These relapses coincide with the period of greatest risk for relapses after stopping Tysabri, in other words 4-8 months after the last infusion. One approach is to stop Tysabri and not attempt pregnancy until you are beyond the risk period for these more severe relapses but undergo frequent MRI and clinical monitoring by your MS specialist during this period to ensure your MS is not becoming too active to attempt pregnancy.  Often we will place individuals on copaxone immediately after the last infusion of Tysabri or even before stopping Tysabri in an attempt to prevent Tysabri withdrawal relapses. The best approach and advice will depend on your individual circumstances. I would suggest discussing this with an MS specialist who has significant experience with the use of Tysabri and managing pregnancy in MS.

PLEASE NOTE:  The medical information on this site is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This information does not create any patient-physician relationship, and should not be used as a substitute for professional diagnosis and treatment.  Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition.