Now that the legislative roadblock to creating biosimilars for the US market has been removed by the recently enacted healthcare reform law, the Affordable Care Act, the debate for the possible regulatory pathway is just beginning. The US Food and Drug Administration (FDA) has previously indicated that the pathway for biosimilars will be very different from that for generic drugs. FDA has further stated that it could take a year or two for the first guidance on the regulatory pathway for biosimilars and that the pathway will constantly “evolve” as the scientific methods to evaluate and characterize biosimilars develop. The biggest attraction for developers of biosimilars is the interchangeability of their products with innovator biologics and the one year of market exclusivity available to the first biosimilar for a given product. More than likely, most biosimilar products would not be considered substitutable. Also, the benefit of one year of market exclusivity pales in the light of 12 years of exclusivity available to new biologics.