Biosimilars differ from generic drugs. A generic drug is an identical copy of a small-molecule drug, for which the same chemical formula and synthesis are used as the originator. Its development takes about 2 years, with costs of about 2 million USD. A biosimilar is not an exact copy of the originator biologic; rather, it may have minor differences in clinically inactive components, particularly since it is made in living cells and the manufacturing process is dependent on reverse engineering. Typical development spans 8-10 years, with costs of up to 200 million USD.