The emergence of follow-on disease-modifying therapies for multiple sclerosis.

Medication prices are a major contributor to the high cost of care for multiple sclerosis. Three generic glatiramer acetate products have regulatory approval in North America, Europe, or Latin America. The pending expiration of patents for other disease-modifying therapies for relapsing multiple sclerosis creates the opportunity for development and regulatory approval of additional follow-on alternatives (generics or biosimilars), potentially providing lower prices and cost savings to payors and patients. However, the complexities of development, regulatory approval, and marketing of follow-on products have some important differences compared to those of new drugs. This topical review provides background and a status update on the development of follow-on disease-modifying medications to treat multiple sclerosis.