Alerts
Natalizumab (Tysabri) Monotherapy and Progressive Multifocal Leukoencephalopathy - UPDATE
January 23, 2012
FDA has been evaluating the risk of progressive multifocal leukoencephalopathy (PML) with natalizumab (Tysabri). As of January 4, 2012, 201 cases of PML have been reported in approximately 96,582 patients treated with natalizumab.
FDA is notifying healthcare professionals that a positive antibody test for anti-JC virus (JCV) can be a risk factor for PML. The Stratify JCV Antibody ELISA test became available in January, 2012 in the US. If a patient tests positive to this test it means they have been previously exposed to JCV. Periodic re-testing of patients with negative antibody tests may be warranted due to potential new exposures to JCV or false-negative readings. Other risk factors for developing PML include extended duration of therapy with natalizumab and prior immunosuppressant medication use. Patients with all three risk factors have an estimated risk of 11/1,000 to develop PML. Consider the risks versus benefits of continuing patients with more than one risk factor for developing PML. Tysabri labeling has been changed to include this new information.
Natalizumab injection (Tysabri) is a monoclonal antibody approved for the treatment of relapsing MS and Crohn disease. Natalizumab is only available to patients through the TOUCH Prescribing Program. Risk for PML is considered to be higher in patients receiving concurrent immunomodulators with natalizumab compared to natalizumab monotherapy.
Closely monitor patients for symptoms of PML and discontinue natalizumab if PML is suspected. Symptoms can include weakness or clumsiness on one side of body, visual changes, or changes in mental acuity.
Additional information can be found through the following links:
- FDA Medwatch Alerts
- January 2012:
http://www.fda.gov/Safety/MedWatch/SafetyInformation/ SafetyAlertsforHumanMedicalProducts/ucm288602.htm?source=govdelivery - February 2010 (updated April 2011):
http://www.fda.gov/Safety/MedWatch/SafetyInformation/ SafetyAlertsforHumanMedicalProducts/ucm199965.htm - September 2009:
http://www.fda.gov/Safety/MedWatch/SafetyInformation/ SafetyAlertsforHumanMedicalProducts/ucm182667.htm - August 2008:
http://www.fda.gov/Safety/MedWatch/SafetyInformation/ SafetyAlertsforHumanMedicalProducts/ucm110599.htm - FDA Drug Safety Communications:
- January 2012:
http://www.fda.gov/Drugs/DrugSafety/ucm288186.htm - April 2011:
http://www.fda.gov/Drugs/DrugSafety/ucm252045.htm - February 2010:
http://www.fda.gov/Drugs/DrugSafety/ PostmarketDrugSafetyInformationforPatientsandProviders/ucm199872.htm - FDA News Release:
- Updated product label and Medication Guide (April 2011):
http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/125104s0438s0475lbl.pdf - Information for Healthcare Providers
Updated
January 23, 2012; April 22, 2011; February 5, 2010; September 22, 2009; August 25, 2008; University of Utah, Drug Information Service. Copyright 2012, Drug Information Service, University of Utah, Salt Lake City, UT.
