Reviewing the evidence for biosimilars: key insights, lessons learned and future horizons.

Biologic therapies have become central to the long-term management of many chronic diseases, including inflammatory rheumatic diseases. Over recent years, the development and licensing pathways for biosimilars have become more standardized, and several biosimilars have been made available for patients with inflammatory rheumatic diseases, such as RA. Pre-licensing requirements for biosimilars mandate the demonstration of comparability with reference products in terms of clinical activity, safety and immunogenicity, whereas post-marketing surveillance and risk minimization requirements are set in place to ensure that long-term, real-world safety data are collected to assess biosimilars in clinical practice. These measures should provide a foundation for physician confidence in biosimilars, which can be established further through clinical experience. Biosimilars may help to fill an unmet need by improving patient access to effective biologic treatments for chronic diseases. Greater access may result in additional clinical benefits, with appropriate use of biologic therapies according to treatment guidelines being associated with improved outcomes and the potential for reduced costs of care. Key challenges for the integration of biosimilars into everyday practice include questions about interchangeability, switching and automatic substitution. Several switching studies have shown that biosimilars can be used in place of reference products while maintaining efficacy and safety. Additional ongoing studies and registries may help to optimize the process of switching, and different funding models are examining the optimal mechanisms to ensure effective uptake of these new treatments.