Dear Healthcare Professional Letter on the case of progressive multifocal leukoencephalopathy in Tecfidera (dimethyl fumarate) treated patient with severe and prolonged lymphopenia


In agreement with the agency for Medicinal Products and Medical Devices (HALMED) and the European Medicines Agency (EMA), Medic Adria d.o.o. is sending a letter to healthcare professionals on the important safety information with regard the case of progressive multifocal leukoencephalopathy (PML) associated with the use of Tecfidera for the treatment of multiple sclerosis.


  • In October 2014, a PML case with a fatal outcome was reported in patient with severe prolonged lymphopenia treated with Tecfidera over 4,5 years. This is the first case of a PML associated with Tecfidera. Patients should be informed that there is a risk of this serious condition
  • Lymphopenia is a known side-effect of Tecfidera and patients should be carefully and often monitor . Complete blood tests, including lymphocyte counts should be monitored regularly and in frequent intervals, according to the clinical indication.
  • Tecfidera-treated patients who develop lymphopenia should be monitored frequently and carefully due to a possible occurrence of signs and symtoms of neurologic disorders.

Further information

Tecfidera is a medicinal product authorised to treat adult patients with relapsing forms of multiple sclerosis (MS). Tecfidera may cause lymphopenia and a decrease in lymphocyte count for about 30%, as revealed by clinical trials. PML is a rare and serious brain infection caused by the JC virus. This is a common virus in general population but can cause PML in some patients who have weakened immune systems (as in the case of lymphopenia). Doctors should adequately inform their patients on the PML risk.

The PML risk for this medicine is currently being assessed at the EU level and healthcare professionals will be promptly informed on the eventual new instructions for use.

Here you may view the Dear Healthcare Professional Letter.

We remind healthcare professionals that they should report any adverse reaction, as well as quality defect to HALMED. Patients who have developed any adverse reaction to medicinal product may report it directly to HALMED via form or on-line application, with recommendation regarding any adverse reaction they discover to consult their doctor or pharmacist about the continuation of their therapy.