Simvastatin as an Add-on Treatment to Interferon-beta-1a for the Treatment of Relapsing-Remitting Multiple Sclerosis

Inclusion Criteria: * Is between the age of 18 and 55 years (both included) * Relapsing-remitting MS according to Poser criteria (CDMS or LSDMS) 22 or definite MS according to McDonald criteria 23 * Disability equivalent to an EDSS of 5.5 or less 21 * Clinical activity defined as at least one reported or documented relapse within the last year * Patient must be prepared to and considered able to follow the protocol during the whole study period and to attend the planned visits, even if the treatment has to be withdrawn Exclusion Criteria: * Any condition that might give rise to similar symptoms as MS * Immunomodulatory or immunosuppressive treatment for MS prior to inclusion into the study (prior pulse steroid treatment for relapses is allowed) * Treatment with glucocorticoids or ACTH later than one month prior to inclusion into the study, i.e. at the screening visit * Onset of a relapse within one month prior to inclusion into the study, i.e. at the screening visit * History of major depression * Alcohol or drug dependency * Cardiac insufficiency, cardiomyopathy, significant cardiac dysrhythmia, unstable or advanced ischemic heart disease (NYHA III or IV) * Significant hypertension (BP \> 180/110 mmHg) * Renal insufficiency defined as serum creatinine \> 1.5 times the upper normal reference limit * Total plasma cholesterol \< 3.5 mmol/L * Any medical illness requiring treatment with systemic corticosteroids * Any systemic disease that can influence the patient's safety and compliance, or the evaluation of the disability * Women who are pregnant, breast-feeding or have the possibility for pregnancy during the study. To avoid pregnancy, women have to be postmenopausal, surgically sterile, sexually inactive or practice reliable contraception