An FDA perspective on the assessment of proposed biosimilar therapeutic proteins in rheumatology.

Biologic products have revolutionized the management of many rheumatic diseases, but access to these products might be limited by their relatively high costs. The US Biologics Price Competition and Innovation Act of 2009, which is contained within the Patient Protection and Affordable Care Act, established an abbreviated pathway for licensure by the FDA of biologic products that are demonstrated to be biosimilar to or interchangeable with FDA-licensed biologic products, termed reference products. This law allows for the approval of biosimilar biologic products, which are expected to increase access to treatment for patients, and ensuring the implementation of this Act is a high priority for the FDA. In this Perspectives article we describe the considerations for approval of proposed biosimilar products, including those to treat rheumatological conditions, by describing the FDA's rigorous approach to assessment of biosimilarity.