The U.S. FDA recently finalized its guidance document intended to assist protein biosimilar manufacturers in demonstrating interchangeability, Considerations in Demonstrating Interchangeability With a Reference Product.  Interchangeability, as of now, is nothing more than a pipe dream; no biosimilar has been declared interchangeable and therefore fully substitutable for its reference product.  But FDA is hoping that this guidance will help address that.  This guidance finalizes FDA’s expectations and updates the draft version of the guidance to provide more clarity.  Of note, this guidance document is directed specifically toward proposed therapeutic protein products. Learn More