Multiple sclerosis is unique among neurological diseases in that
there are currently eight treatments for this one condition that
have received approval by the U.S. Food and Drug Administration
(FDA). Five of these drugs require subcutaneous or intramuscular
injection, two are administered intravenously, and fingolimod,
the newest agent on the block, is given orally. None are
considered curative, but these disease-modifying therapies (DMT)
have led to a reduction in relapse rates and the progression of
disability. Despite this progress, each of the drugs comes with
side effects, including flu-like symptoms with the interferons,
lipoatrophy with glatiramer, progressive multifocal
leukodystrophy (PML) with natalizumab, and congestive heart
failure or leukemia with mitoxantrone. As the first oral agent
for MS, fingolimod created great expectations prior to FDA
approval. Its popularity, however, has been surprisingly
limited, presumably due to the potential for unknown long-term
risks. The occur rence of PML with