Assess safety profiles of dimethyl fumarate (DMF) and fingolimod (FTY) by utilizing data from the FDA Adverse Event Reporting System (FAERS) database.

The numerous disease modifying therapies (DMTs) approved for relapsing multiple sclerosis (MS) allows for optimized individualized treatment, but selection has become increasingly challenging. Considerable effort has been devoted to comparative efficacy between DMTs, but data for comparative safety are more limited.

Data were downloaded from the FAERS database in April 2020.  Adverse event (AE) reports were gathered for the most common AEs included in the medication labels. They were filtered to include only those reported by healthcare professionals and  reported as serious.   Events were excluded if there were multiple suspect products named.  Data were normalized to patient years (PY) for each DMT - 875,000 for DMF (reported in January 2020) and 778,900 for FTY (reported in February 2020). Inferential statistics were derived from Poisson rate models using SAS 9.4.

0.616 and 0.003(RR=179.741, p<0.001), cryptococcal infection 0.0654 and 0.0023(RR=28.646, p<0.001), and flushing 0.099 and 0.493 (RR=0.201, p<0.001)-.

Comparative safety data between FTY and DMF are presented and suggest a safety advantage of DMF over FTY in risk of PML, viral infections, herpes infections, transaminitis, malignancy, macular edema, and cryptococcal infection, while DMF is associated with more flushing than FTY. There was no difference in the rare complication of angioedema between both DMTs.