Notice: eScholarship will undergo scheduled maintenance from Tuesday, January 21 to Wednesday, January 22. Some functionality may not be available during this time. Learn more at eScholarship Support.
Fingolimod is a sphingosine 1-phosphate receptor modulator approved for relapsing MS. Long-term effects on the immunological profile are not fully understood.
Objective
Investigate fingolimod's temporal effects on immune cell subsets, and safety outcomes.
Methods
In FLUENT, a 12-month, prospective, non-randomized, open-label, phase IV study, adult participants received fingolimod 0.5 mg/day. Changes in immune cell subsets, anti-John Cunningham virus (JCV) antibody index, and serum neurofilament levels were assessed.
Results
165 fingolimod-naive and 217 participants treated for 2-12 years in routine clinical practice were enrolled. Levels of all monitored peripheral lymphocyte subsets were reduced from month 3 in fingolimod-naive participants. Greatest reductions occurred in naive and central memory CD4+ and CD8+ T cells, and in naive and memory B cells. Most lymphocyte subset levels remained stable in the continuous fingolimod group. Components of the innate immune system remained within reference ranges. No increase in JCV seropositivity was observed. No single cellular subset correlated with anti-JCV antibody index at any time point. Neurofilament levels remained within healthy adult reference limits throughout. No opportunistic infections were reported; no new or unexpected safety signals were observed.
Conclusion
FLUENT provides insights into the utility of immunological profiling to evaluate therapy response and potential infection risk.
