A biosimilar, per FDA, is a biologic medication that is highly similar to and has no clinically meaningful differences from an existing FDA-approved biologic, called a reference product. Compared with a reference product, biosimilars: are made with the same types of living sources, are given to the patient in the same way, and have the same strength, dosage, potential treatment benefits, and potential side effects. Unlike small-molecule generic drugs biologics generally exhibit high molecular complexity and may be quite sensitive to changes in manufacturing processes. Despite that heterogeneity, all biopharmaceuticals, including biosimilars, must maintain consistent quality and clinical performance throughout their lifecycle. FDA’s biosimilar approval process provides assurance that biosimilars provide the same treatment benefits and risks as their respective reference products. Biosimilars have made biologics more available and (somewhat) more affordable. Follow the link for a very interesting if slightly dated overview of the utilization and future of biosimilars in US healthcare.