USP, Apotex and researchers weigh in on FDA’s draft guidance on biosimilarity

Released in May, the draft guidance​ aims to help biosimilar developers design and use clinical pharmacology studies to support regulatory decisions on whether a proposed biologic is biosimilar to its reference product.

Researchers from the Statistical Scientific Advisory Board (SSAB) on Biosimilars, which was established by Amgen in 2009, go into the furthest detail in their comments​. The researchers seek further clarity on the demographic groups for clinical pharmacology studies that would most likely “provide a sensitive measure of differences between the proposed biosimilar product and the reference product.” They specifically seek clarity on whether to view biosimilarity studies as quality control procedures, or as surrogates of the relevant clinical conditions.

In addition, the researchers offer a unique biosimilarity index to be used by the FDA, and that cases when the use of reference-scaled average bioequivalence, when warranted, be incorporated into new guidance.

Apotex​

Drugmaker Apotex, meanwhile, limits its commentary and notes a number of points that the company would like further clarity on. For instance, the company seeks a definition for the term “biosimilarity” as there could be other factors that contribute to it, other than efficacy and potency.

The company also seeks more clarity on pharmacodynamics biomarkers, cases of when to provide justification “as to the failure to detect free and/or active forms of the product does not compromise the pharmacokinetic similarity assessment​,” and further directions on the timeline for the storage of samples.

USP​

USP notes that its standards “may be helpful for informing FDA’s evaluation​,” though only the FDA may make findings regarding biosimilarity, and only the FDA can determine on a case-by-case basis what role if any an applicable compendial standard should play in the its deliberations.

In the US, only the FDA has the authority to determine that two drugs are the same, similar, identical, or interchangeable.

“Where two biologics share a compendial identity, this does not mean they are one and the same drug; only that they are subject to one and the same USP standard for quality. There is well-established precedent in this area; insulin, somatropin, and glucagon are all examples of non-interchangeable, multi-manufacturer drugs that share a single USP compendial standard​,” USP says.

And Biopharma-Reporter will be delving deeper into the issues affecting biosimilars with a free virtual event on September 26. Join four industry experts as they discuss the development, manufacture and sale of such products in a 60 minute seminar hosted by our Editor-in-Chief Gareth Macdonald. Click here​ for more details...