Here’s a brief look at some of the major discussions happening now:
Naming: The ACR’s position is that distinguishable, non-proprietary names for biosimilars, rather than generic names, will help ensure correct prescribing and dispensing of these drugs. We think distinct names will improve post-marketing monitoring for safety and efficacy, increase prescriber and patient confidence, and enhance market uptake. We expect the FDA to release its naming methodology standards shortly. If they stick with using distinct names, it may help enable them to make enforceable, science-based assessments of biosimilars, including extrapolation and interchangeability.
Labeling & Extrapolation: The ACR supports clear product labeling that indicates whether a biosimilar is interchangeable with its reference biologic. We feel that labeling should list all of the biosimilar’s approved indications and specify whether supporting clinical data were derived from studies of this biosimilar or its reference drug. The FDA released on March 31 draft guidance for industry that incorporates this recommendation. We’ve advised the FDA to use caution when approving extrapolation of biosimilars for indications that were already approved for the reference biologic. Why? Because there would be no safety data specific to that biosimilar and patient population.
One example illustrating this very real patient risk relates to biosimilars for erythropoietin. There are a few brands of erythropoietin on the market globally. In at least one instance, even though the biosimilar product and the reference product had similar therapeutic efficacy, one product had a different toxicity. Some people given the biosimilar developed immunity to the erythropoietin, which caused them to develop immunity to their own erythropoietin. This demonstrates how a biosimilar product that otherwise had characteristics that were identical to those of the reference product, had different toxicities. This immunogenicity development likely occurs in the highly complex manufacturing process that uses active cell lines. Such variations present a challenge in developing biosimilars, and are one concern with using them.1
Interchangeability: Although no manufacturer has yet applied for an interchangeable designation for a biosimilar, it will happen in the future. Interchangeables must meet higher standards of similarity to the reference biologic, and if so, they can be substituted by the pharmacy with no notification or prior approval from the prescriber. The regulatory criteria for interchangeability are still being developed, and the FDA has suggested that it will provide more information and clearer guidance on this issue in 2016. Many states have already passed laws to limit substitution at the pharmacy without prescriber notification. Obviously, this issue is of critical importance to rheumatology providers.
