Natalizumab (marketed as
FDA ALERT [8/2008]: The FDA has recently received information from the manufacturer about two new cases of progressive multifocal leukoencephalopathy (PML) in patients receiving Tysabri monotherapy for multiple sclerosis in Europe. Both patients had received Tysabri for more than one year. PML, which is usually fatal, is a known risk of Tysabri treatment, but previous cases in patients with multiple sclerosis were seen in combination with other immunomodulatory therapies. About 39,000 patients have received treatment with Tysabri worldwide, with about 12,000 patients having been treated for at least one year. No new cases have been seen in the US, where about 7,500 patients have received the drug for longer than one year and about 3,300 patients have received the drug for at least one and a half years.
In the U.S., Tysabri is available only to patients with relapsing multiple sclerosis (MS) or Crohn's disease (CD) who are enrolled in the risk minimization plan called the TOUCH Prescribing Program. Under the TOUCH Prescribing Program, every Tysabri-treated patient is closely monitored and followed for the occurrence of PML and other serious opportunistic infections.
While the two patients who developed PML were on monotherapy, the FDA still believes that Tysabri monotherapy may confer a lower risk of PML than when Tysabri is used together with other immunomodulatory medications.
The FDA is working with the manufacturer to amend the product labeling to inform prescribers and patients that cases of PML have occurred in patients taking Tysabri as monotherapy.
This information reflects FDA's current analysis of data available to FDA concerning this drug. FDA intends to update this sheet when additional information or analyses become available.
To report any serious adverse events associated with the use of this drug, please contact the FDA MedWatch program and complete a form online at http://www.fda.gov/medwatch/report.htm or report by faxing (1-800-FDA-0178), by mail using the postage-paid address form provided online, (5600 Fishers Lane, Rockville, MD 20852-9787), or by telephone (1-800-FDA-1088).
The Food and Drug Administration (FDA) today (June
5, 2006) approved an application for resumed marketing of Tysabri (natalizumab)
with a special restricted distribution program. Tysabri is a
monoclonal antibody, for the treatment of patients with relapsing
forms of multiple sclerosis (MS). Tysabri is indicated for use as
monotherapy, because we don't know enough about how its use with
other immune modifying drugs could impact risk. It is also meant for
patients who have not responded adequately to, or cannot tolerate,
other treatments for MS.
Tysabri was initially approved by the FDA in November, 2004, but was
withdrawn by the manufacturer in February 2005 after three patients
in the drug's clinical trials developed progressive multifocal
leukoencephalopathy (PML), a serious viral infection of the brain.
FDA then put clinical trials of the drug on hold in February, 2005,
allowing them to resume a year later after confirming that there
were no additional cases of PML. In March, 2006, FDA consulted its
Advisory Committee on drugs for peripheral and central nervous
systems about the possibility of making Tysabri available to
appropriate MS patients. The Advisory Committee recommended a
risk-minimization program with mandatory patient registration and
periodic follow-up. In response, the manufacturer, Biogen-Idec
submitted to the agency a Risk Management Plan to help ensure safe
use of the product. Tysabri is available only through the Risk
Management Plan, called the TOUCH Prescribing Program. In order to
receive Tysabri, patients must talk to their doctor and understand
the risks and benefits of Tysabri and agree to all of the
instructions in the TOUCH Prescribing Program.
Back to Drug Index
PDF requires the free Adobe
Date created: February 28, 2005, updated August 25, 2008