As the Food and Drug Administration (FDA) begins to deemphasize the interchangeability designation, with an eye towards making any approved biosimilar interchangeable with the reference product, an expert panel at this week’s GRx+Biosims 2024 conference tackled the prevailing issue: Does interchangeability matter today?
One major detail underlying this discussion was not specifically mentioned: An interchangeability designation has not been utilized widely in any drug category to achieve its intended purpose—to enable a quick conversion from the reference drug to the interchangeable biosimilar. Hyrimoz® and its Cordavis private-label version achieved a rapid conversion from Humira in April 2024; however, neither of these products had earned the interchangeable designation. It was simply achieved through a formulary policy switch by the PBM.
The panel evaluated the overall question from the standpoint of retail pharmacies, manufacturers, managed care pharmacists, and a group purchasing organization. Michelle Cope, Director of Federal & State Pharmacy & Regulatory Affairs, National Association of Chain Drug Stores, pointed out that “in accordance with law, pharmacies can substitute an interchangeable product for a reference biologic, but this is not happening much because of plan coverage/preferences.” What she has seen is streamlined processes established at the pharmacies for prescriber notification if automatic substitution took place. She emphasized that this is not an automated process, which could be most efficient if dealing with a high volume of substitutions.
Sam Leo, Senior Director, US Biosimilar Operations, Teva Pharmaceuticals, elaborated on the confusion that exists with the term interchangeability. “The term itself creates a certain level of comfort for stakeholders, even though this may not be a correct perception).” He speculated that a switch to an interchangeable product might be better received by a patient than a switch to a conventional biosimilar. Of course, this would be dependent on the clinician or pharmacist describing the new agent to the patient, rather than simply writing a prescription for it or dispensing it.
Heather Pace, PharmD, Senior Clinic Manager, Vizient, noted their providers’ confusion over the interchangeability. “This extends to not only which formulations of a product are interchangeable (i.e., specific low-concentration vs. high-concentration adalimumab products) and when the exclusivity associated with the designation will expire,” she stated. “While we do have the body of literature regarding biosimilars and their safety and efficacy of interchangeability, the designation itself is confusing.”
“The exclusivity provision is an important incentive for manufacturers to continue to seek the designation,” stated Sam Leo. “If interchangeability goes away, exclusivity goes away, too.”
The FDA is not necessarily awaiting an act of Congress to address biosimilar interchangeability. It has taken a number of actions, including the removal of any requirement for switching studies in order to obtain the designation.
Adam Colborn, JD, Associate Vice President, Congressional Affairs, Academy of Managed Care Pharmacy, said that FDA’s actions are a step in the right direction, but the interchangeability provision is written into the BPCIA. “If you want to change the law, you need legislation to do that,” he reminded the attendees. He doesn’t think the FDA can do it on its own. “And it doesn’t look like the existing legislative proposals on it will pass this year,” according to Mr. Colborn. “We just need to get across the finishing line in making biosimilarity and interchangeability the same thing. We shouldn’t see the same partisan disagreement that we see on PBM reform,” which could help the legislative process along.
