Therapeutic proteins continuously acquire higher shares of the pharmaceuticals market. Monoclonal antibodies, for example, show double-digit growth rates and also proteins which have been known for a longer period of time, such as interferon-β (IFN-β) exhibit an annual turnover of three billion US dollars. Treatment with IFN-β is one of the current basic therapies for the most frequent form of multiple sclerosis (MS), relapsing-remitting MS. The costs for IFN-β treatment in Germany amount to 18,000 euros per patient and year with the consequence that the majority of the 2.5 million MS patients worldwide cannot be adequately treated with IFN-β. In this context, the required quantities of active substances at 45 mg per patient and year for IFN-β-1b are very small.