The purpose of this study is to compare the pharmacokinetics of FTY720 and its metabolites in patients with severe renal insufficiency and in matched, healthy volunteers. This study will allow a better understanding of the effects of renal insufficiency on the disposition of FTY720.

Inclusion Criteria:

Healthy Subjects:

• Subjects must have a calculated glomerular filtration rate (GFR) by Cockcroft-Gault Equation ≥80 mL/min.

Severe Renal Impaired Patients:

• Patients not on dialysis with severe renal failure with a creatinine clearance < 30 mL/min as determined by Cockcroft-Gault Equation.
• Renal function should have been stable within the 3 months prior to study start.
• Patients with diabetes and/or hypertension who are in otherwise in good health may be included. However patients with diabetes must not have clinical evidence of gastropathy or enteropathy.

Exclusion Criteria:

All Subjects/Patients:

• History of multiple and recurring allergies or allergy to the investigational compound/compound class being used in this study
• History of retinal macular edema.
• History of any significant cardiovascular events such as myocardia infarction, valvular disease, angina, ischemic heart disease, dilated cardiomyopathy, dysrhythmia.
• History of immunocompromise, including a positive HIV (ELISA and Western blot) test result.

Severe Renal Impaired Patients:

• Use of any highly potent CYP3A4 inhibitor (e.g. erythromycin, ketoconazole, itraconazole) within 2 weeks prior to dosing.
• Use of beta blocker therapy within two (2) weeks prior to dosing.

Other protocol-defined inclusion/exclusion criteria may apply