By Vien Lai
Quick Perspective on Considerations in Demonstrating Interchangeability With a Reference Product
The requirements for approval of 351(k) interchangeable biosimilar products are similar to that of 351(k) biosimilar biologics, but additional data are needed to support the interchangeability. However, it was unclear what “additional data” would be required.
After a long period since the existence of the guidance for “biosimilar” and the availability of several biosimilar products, on January 12, 2017 the Food and Drug Administration released the draft guidance for industry entitled Considerations in Demonstrating Interchangeability With a Reference Product for biologics.
The main impact of this guidance is the design and analysis of the switching study (or studies). It is very helpful to know that interchangeability can be demonstrated by satisfaction of bioequivalence limits of 80–125% based on pharmacokinetic pivotal parameters in combination with pharmacodynamic endpoints, when evaluated. Instructions for design of the integrated study where demonstration of biosimilarity and the impact of switching between the reference product and the proposed product for interchangeability are also outlined. The delay (until now) of this guidance is really a pity for already-approved biosimilar products as the sponsors should have had this guidance to demonstrate interchangeability of their products. Note that interchangeable biologics can be given to the patients by the pharmacist without counseling the prescriber. This obviously warrants a greater market share.