What Are Interchangeable Biologics?

Monday December 11, 2023

The U.S. biosimilar market continues to grow, with new adoption, new approvals and, most recently, new proposed FDA guidance to simplify and clarify biosimilar and interchangeable biosimilar product labeling. To be sure, the explosive growth of the biosimilars market in recent years has expanded the availability of treatment options for patients. Biosimilar availability resulted in more than 344 million additional days of patient therapy that otherwise wouldn’t have occurred. Among these options are those deemed “interchangeable” which is a specific designation given to certain versions of these products. But confusion about what an “interchangeable” designation actually means continues to undermine patient access to lower-cost biosimilars. So what are interchangeable biologics?

According to the FDA, “An interchangeable biological product is a biosimilar that meets additional requirements and may be substituted for the reference product at the pharmacy, depending on state laws.” Essentially, this means that if a patient is prescribed a brand biologic by their physician, the patient’s pharmacist can automatically dispense the interchangeable biologic in its place without intervention from the physician.

For a product to receive an “interchangeable” designation, the manufacturer must submit additional data to the FDA to prove that it can be seamlessly substituted without impacting a patient’s treatment plan. As GoodRx notes, “This doesn’t mean that interchangeable biosimilars are better than regular biosimilars. All biologics and biosimilars have to meet strict quality and safety regulations. But this extra data allows them to be substituted more easily at the pharmacy.”

In a recent blog post, Dr. Yim Sarah Yim, M.D., director of the FDA’s Office of New Drugs’ Office of Therapeutic Biologics and Biosimilars, reinforced this idea around sameness and the need to reduce misunderstanding between the two designations, affirming that, “there may be inaccurate perceptions that interchangeable biosimilars are safer or more effective than biosimilars that are not approved.” She furthered that point at our GRx+Biosims 2023 conference in October, stating that, “Scientifically, biosimilars and interchangeables are really not distinguishable.” Put simply, an interchangeable designation only impacts ease of access, not the quality of the drug.

Whether a biosimilar is designated as “interchangeable” depends on the choice of the manufacturer. Once a manufacturer develops a product, and it is rigorously tested and approved by the FDA, manufacturers can choose to market it right away. If they want it to be “interchangeable,” the manufacturer submits additional data for the FDA to review.

But biosimilars that do not have interchangeable designations are not inferior in efficacy or safety profiles. Rather, this could simply mean that the manufacturer chose not to pursue the costly process of submitting additional data to allow for pharmacy-level substitution.

All approved biosimilars are safe and effective treatment options that cost significantly less than brand-name biologics. Patients can trust that, whether they receive a biosimilar or an interchangeable biologic, these products will help them save money while achieving their treatment goals.

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GRx+Biosims™ 2024 is the leading regulatory science and policy event for the U.S. generics and biosimilars industry. Access the most recent information straight from experts at the Food and Drug Administration, grasp the latest policies shaping the industry, and acquire valuable insights to propel your professional development.