The challenge of follow-on biologics for treatment of multiple sclerosis

Intellectual property protections for biologic medicinals for multiple sclerosis (MS) are beginning to expire, opening the possibility of development, regulatory approval, and marketing of so-called follow-on biologics, biosimilars, or subsequent entry biologics that might be offered at lower price to consumers and third-party payers, as has been the case for generic drugs. Determining the comparability of a follow-on biologic to its innovator product is more difficult than for small-molecule drugs because of the greater complexity of biologics and the possibility that manufacturing differences can introduce differences in biologic activity and immunogenicity that could result in unpredictable differences in safety or efficacy. We provide a perspective on issues surrounding development, regulatory approval, and potential use of follow-on biologics, with an emphasis on disease-modifying agents for MS.