On January 17, 2017, the Food and Drug Administration (FDA) released a draft guidance intended to assist sponsors in demonstrating that a biosimilar is interchangeable with a reference product. This guidance specifically focuses on therapeutic protein products and gives an overview of FDA’s thinking on what FDA expects to be included in the data package that sponsors would submit to demonstrate interchangeability. Remarkably, the guidance does not address how interchangeable products will be named by FDA, an issue left open in final guidance on biosimilar naming that was previously released. Some takeaways from the draft guidance are as follows.
Interchangeability Standard
By law, a biosimilar is interchangeable with the reference product if FDA determines that the information submitted in the application is sufficient to show that the biological product “can be expected to produce the same clinical result as the reference product in any given patient” and that for products administered more than once, the risk of switching between the biological product and the reference product is “not greater than the risk of using the reference product without such alternation or switch.” Once interchangeability is demonstrated, “the biological product may be substituted for the reference product without the intervention of the health care provider who prescribed the reference product.”
FDA’s Process for Review
The FDA recommends that sponsors use a stepwise approach in “generating data and information to address residual uncertainty about demonstrating interchangeability during product development.” FDA says it intends to consider the totality of the evidence, noting that “the product’s degree of structural and functional complexity may also influence the data and information needed to support a demonstration of interchangeability.” FDA continues, “the data and information to support a [finding of interchangeability] may vary depending on the nature of the proposed interchangeable product.” While seeking licensure for only one reference product condition is permissible, FDA recommends that sponsors seek licensure for all of a reference product’s conditions of use when possible.
Switching Studies
FDA expects that applications will include data from a switching study or studies in one or more appropriate conditions of use. In doing so, FDA is addressing the legal standard that “the risk in terms of safety or diminished efficacy of alternating or switching between use of the biological product and the reference product is not greater than the risk of using the reference product without such alternation or switch.” FDA says the main purpose of a switching study or studies “is to demonstrate that the risk in terms of safety or diminished efficacy of alternating or switching between use of the proposed interchangeable product and the reference product is not greater than the risk of using the reference product without such alternation or switch.”
Post-Marketing Data
FDA believes that postmarketing data from a licensed biosimilar product may be “helpful as a factor when considering what data is necessary to support a demonstration of interchangeability.” FDA notes, however, that “our current thinking is that postmarketing data collected from products first licensed and marketed as a biosimilar, without corresponding data derived from an appropriately designed, prospective, controlled switching study or studies, generally would not be sufficient to support a demonstration of interchangeability.”
Reaction from the American College of Rheumatology
Dr. Angus Worthing, MD, FACP, chair of the ACR’s Government Affairs Committee notes, “The ACR is pleased to see the FDA issue draft guidance on biosimilar interchangeability. This guidance brings us one step closer to the shared goal of lowering prices in the biologics marketplace. While the ACR is still reviewing the document and will provide detailed comments to the FDA in the coming weeks, our initial reaction is that the draft guidance strikes a good balance between ensuring safety and efficacy while also getting biosimilar products to market as efficiently as possible.”
Dr. Worthing continued, staying, “We also applaud the FDA for suggesting clinical studies which switch back and forth, not just one-way from the reference drug to the biosimilar. The use of at least two exposure periods to each drug will mimic to some extent what our patients are likely to experience with changing formularies in a multi-payer, multi-state, ever-changing market.”
Conclusion
Comments on the guidance should be submitted within 60 days (by March 20, 2017) to ensure FDA consideration before it begins working on a final version. FDA also poses questions for stakeholder feedback related to (1) considerations behind regulating post-approval manufacturing changes of interchangeable products, and (2) how the FDA should approach a situation when a reference product is approved for a new condition after an interchangeability determination has been made for a related product.