In a 6-month, placebo-controlled trial, oral fingolimod (FTY720) 1.25 or 5.0 mg, once daily, significantly reduced MRI inflammatory activity and annualized relapse rate compared with placebo in patients with relapsing multiple sclerosis (MS). The objectives were to monitor the 36-month, interim efficacy and safety results of the ongoing extension of this study. In the extension (months 7-36), placebo-treated patients were re-randomized to either dose of fingolimod; fingolimod-treated patients continued at the same dose. During months 15-24, all patients receiving fingolimod 5.0 mg switched to 1.25 mg. Of the 250 patients who entered the extension study, 173 (69%) continued to month 36. Most patients were free from gadolinium-enhanced lesions (88-89%) or new T2 lesions (70-78%) at month 36. Patients receiving continuous fingolimod treatment had sustained low annualized relapse rates of 0.20-0.21, and 68-73% remained relapse-free at month 36. Over 36 months, nasopharyngitis (34%), headache (30%), fatigue (19%) and influenza (18%) were the most commonly reported adverse events. Pulmonary function remained stable and blood pressure was stable after an initial increase (3-5 mmHg) during the first 6 months of fingolimod treatment; serious adverse events included infections and skin cancer. The low MRI and clinical disease activity at 6 months were maintained at 36 months with fingolimod, which was generally well tolerated by most patients. The efficacy and safety of oral fingolimod are being further evaluated in a large phase III MS study programme.