PML has been diagnosed in patients receiving either Tecfidera for MS or Fumaderm for Psoriasis. Prolonged lymphopenia (lymphocyte count <0.5) appeared to be a risk factor for PML. In the MS placebo controlled trials, mean lymphocyte counts decreased by approximately 30% during the first year of treatment with Tecfidera then remained stable at this reduced level for the duration of treatment. Six percent (6%) of Tecfidera patients experienced lymphocyte counts < 0.5×109/L and remained so for the duration of treatment. Lymphocyte count begin to improve 4 weeks after stopping Tecfidera. The time to recovery to baseline however has not been established. PML has however been reported in fumarate treated patients without associated lymphopenia.
The starting dose for TECFIDERA is 120 mg twice a day orally, for a total of 240 mg per day.
After 7 days, increase to the recommended dose of 240 mg twice a day orally, for a total of 480 mg per day.
Temporary dose reduction to 120 mg twice a day (total of 240 mg per day) may reduce the occurrence of flushing and gastrointestinal (GI) side effects. Within one month, the recommended dose of 240 mg twice a day orally should be resumed.We however suggest to start at 120 mg once per day and increase by 120 mg per day every week up to the recommended dose of 240 mg twice a day. Slower increase in dosage appear to improve overall tolerability.