Safety and tolerability of fingolimod 0.5 mg during the first 4 months of administration in patients with relapsing forms of multiple sclerosis. Results from the open-label, multicentre FIRST study - Kappos, L; Comi, G; Palace, J; Siever, A; Marrosu, M; Mehling, M; Gottschalk, R; Bijarnia, M; Keil, A; Tomic, D; von Rosenstiel, P; Gold, R (2012)