In December 2014, important label changes were made
to the prescribing information for Tecfidera® (dimethyl fumarate, Biogen Idec)
including information regarding an individual who developed PML. Most recently,
Biogen has confirmed report of a second case of PML (progressive multifocal
leukoencephalopathy, a viral infection of the brain that often leads to death
or severe disability) that occurred in a person taking Tecfidera. According to
the company, the 64-year-old patient has primary progressive MS and experienced
severe and prolonged lymphopenia (decreased white blood cells) during treatment
with Tecfidera. Severe and prolonged lymphopenia is a known risk factor for PML
and Consideration should be given to interrupting treatment if lymphocyte
counts are low for more than six months. The patient is stable and is not
hospitalized. Biogen has reported the case to the U.S. Food and Drug
Administration (FDA).
PML is caused by the re-activation
of a virus called the JC (John Cunningham) virus, a common virus to which many
people have been exposed. PML has emerged in people using other medications,
including the MS treatment Tysabri® (natalizumab, Biogen), and the MS treatment
Gilenya® (fingolimod, Novartis AG).
It is not possible at this
point to determine a person’s risk for developing PML because there have been
so few cases in people taking Tecfidera. There have been two reported cases of
PML in people with MS among the more than 155,000 individuals who have been
treated with Tecfidera to date.
The symptoms of PML are
diverse and can be similar to MS symptoms. For this reason, individuals should
be alert to any new or worsening symptoms and report them promptly to their MS
healthcare provider. Learn more about the risk factors and symptoms of
PML from the web site of The PML Consortium. Individuals who have concerns
about this report should discuss it with their MS healthcare providers.
If and when the FDA or Biogen
provide additional information or recommendations for people taking Tecfidera
or other MS medications, the National MS Society will share it as soon as
possible.