Answer
Yes, cases of progressive multifocal leukoencephalopathy (PML) have been reported with siponimod fumaric acid.
Sources for this answer
- Mayzent 0.25 mg, 1 mg & 2 mg film-coated tabletsNovartis Pharmaceuticals UK Ltd · emc · SmPC §4.4 Special warnings and precautions for use · Version 8Document updated
Sources checked