At the end of July 2008, the European Medicines Agency (EMEA) received two
reports of progressive multifocal leukoencephalopathy (PML) in patients with
relapsing-remitting multiple sclerosis (MS) who have been treated with Tysabri
PML is a rare brain infection with symptoms
that are similar to those of an MS attack. The two cases occurred in patients
who have been treated for MS with Tysabri only for more than 12 months. The two
cases were reported as part of the continuous safety-monitoring of medicines
following their authorisation and placing on the market.
The risk of PML
with Tysabri is known and is kept under close monitoring by the EMEA. The
product information advises healthcare professionals that the medicine must not
be used in patients who have PML and that patients taking Tysabri should be
regularly monitored for signs and symptoms suggestive of PML.
cases are currently being assessed by the EMEA's scientific Committee for
Medicinal Products for Human Use (CHMP). Elan, the marketing authorisation
holder for Tysabri, has also been asked to provide any additional information
they may have. Following assessment of all available data, the CHMP will
determine whether any changes to the currently approved product information or
the existing risk minimisation measures, including the 'Physician Information
and Management Guidelines for Multiple Sclerosis Patients on Tysabri' are
1. Tysabri is used to treat
relapsing-remitting MS in patients with high disease activity despite treatment
with a beta-interferon or whose disease is severe and progressing
2. More information about Tysabri is available on the EMEA website.
3. The 'Physician
Information and Management Guidelines for Multiple Sclerosis Patients on
Tysabri' are part of the agreed risk management plan for Tysabri. In accordance
with this plan, the marketing authorisation holder for Tysabri committed to
provide an information pack to all physicians who intend to prescribe Tysabri.
The pack contains, among other elements, also information about the diagnosis
and management of PML. For more information see here.European Medicines Agency