The FDA’s recently published draft guidance titled Development of Therapeutic Protein Biosimilars: Comparative Analytical Assessment and other Quality-Related Considerations (here) is a significant improvement over the withdrawn 2012 guidance (i.e., Quality Considerations in Demonstrating Biosimilarity to a Reference Protein Product) that it replaced.  The increased level of detail and wider breadth of topics gives a significantly better view of the information that the Agency wishes to see in a BLA for a biosimilar product.