The EMA (European Medicines Agency) recommends that if an MSer has a persistent lymphopaenia of below 200/mm3 (grade 4 lymphopaenia) then fingolimod should be stopped until the lymphocyte counts recover. It is our practice to put these patients on alternate day fingolimod and to rechallenge them with the full dose once the counts have recovered to above 200/mm3.
Now that fingolimod has been licensed for treating children with MS, with a dose based on weight, a 0.25mg tablet will become available. So instead of taking 0.5mg alternate days there is also the possibility of taking 0.25mg daily.
As the response to fingolimod and the risk of opportunistic infections are unrelated to the lymphocyte counts the FDA (Food and Drug Administration, US) has not recommended routine monitoring of lymphocyte counts. Because of this I am not that concerned about lymphocyte counts in patients on fingolimod and tend to only respond to counts of less than 100/mm3.
Although the Gilenya SmPC recommends that when switching from a 0.25 mg to a 0.5 mg daily dose the same first dose monitoring as for treatment initiation should be undertaken we have not done this. The following text is from the Gilenya SmPC:
Please note that the same first dose monitoring as for treatment initiation is recommended when treatment is interrupted for:
- 1 day or more during the first 2 weeks of treatment.
- more than 7 days during weeks 3 and 4 of treatment.
- more than 2 weeks after one month of treatment.
If the treatment interruption is of shorter duration than the above, the treatment should be continued with the next dose as planned.