The FDA has approved a second biosimilar drug, infliximab-dyyb, which is indicated for treating several rheumatic diseases. The drug is biosimilar to the tumor necrosis factor α inhibitor infliximab, which originally was licensed in 1998 (http://1.usa.gov/1RWO6BF).
Approval of biosimilar products is based on evidence showing high-level similarity to an already approved biological product, known as the reference product. The FDA can approve a biosimilar product only if it has the same mechanism of action, route of administration, and dosage form and strength as the reference product. Facilities where biosimilars are manufactured also must meet FDA standards.
Rebecca Voelker. Second Biosimilar Approved. JAMA. 2016;315(19):2057. doi:10.1001/jama.2016.5597