The purpose of the study is to evaluate the safety and tolerability of a combination of interferon beta 1-b (Betaseron®) and tacrolimus (Prograf®) in patients suffering from multiple sclerosis (MS) who have failed treatment with currently approved drugs for MS

Prograf is an immunosuppressant that weakens the immune reactions responsible to protect the organism against infections. It is currently available on the market for patients who have received an organ transplant, to prevent rejection. Because of its effect on the immune system, theoretically, Prograf should exert a significant effect in MS. It has been tried in a small number of MS patients at a lower dose than the one used in organ transplant, however the results of the study did not allow to draw definite conclusions on its safety and efficacy in MS.

Betaseron is approved in Canada for the reduction of the frequency of relapses in patients with relapsing-remitting MS and for the slowing of progression and reduction of the frequency of relapses in patients with secondary-progressive MS. The combination of Betaseron and Prograf may result in an additive effect or an increase in the actions of the drugs. However, the combination of the two drugs has never been studied.

The aim of this study is to see how well the combination of Betaseron and Prograf is tolerated by patients with MS. The side effects of the treatment, if any, will be followed. In addition, the efficacy of the combination will be evaluated.