Boehringer Ingelheim has filed a Citizen Petition to the US FDA to change its interpretation of how the strength of a biosimilar is determined.

Boehringer Ingelheim filed the petition to the US Food and Drug Administration (FDA) last week to change the interpretation of the word ‘strength’ to mean total drug content. Currently, the FDA’s interpretation is based on both the total content of drug substance and the concentration of drug substance.

In its Citizen Petition, Boehringer claims that this can lead to manufacturers ‘evergreening’ their products. A spokesperson for Boehringer told us that the “FDA’s current definition encourages, or at least permits, manufacturers to use minor concentration changes as an anti-competitive tactic.”

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This is of particular concern to the company due to its development of Cyltezo (adalimumab), a biosimilar to AbbVie’s Humira. In addition, in 2018, Boehringer chose to concentrate its efforts in biosimilars solely to the US market.

In the Citizen Petition, Boehringer states “[Biosimilars] should be considered to have the same “strength” as the corresponding OC (original concentration) and HC (higher concentration) versions of Humira because they contain the same total drug content per container (e.g., 40 mg), regardless of the volume of excipients.”

As to why the issue over concentration is limiting for biosimilar developers, the spokesperson said, “FDA’s current interpretation completely forecloses licensure of biosimilar and interchangeable products with concentration differences from the reference product, even if they could be proven to have no clinically meaningful differences in terms of safety, purity or potency than the reference product.”

The company adds that this is preventing any of the currently authorized biosimilar products to Humira at the OC formulation to be considered as a biosimilar or interchangeable with the product’s HC version.

Further than this, Boehringer outlines that a change to the FDA’s current understanding of ‘strength’ would “ensure the Agency’s interpretation is consistent with the clear meaning of the Biologics Price Competition and Innovation Act” and “maintain fair and consistent treatment of all similarly situated parenteral biological products.”

As to what benefits changing the definition could provide beyond those provided to biosimilar manufacturers, the spokesperson added that it could lead to ‘more robust’ use of biosimilar products, benefitting the US healthcare system and providing greater access to ‘affordable biological products’.