"Biosimilars are not generic drugs and should not be labeled like generic drugs," US pharmaceutical giant AbbVie argues in a new Citizen Petition sent to the US Food and Drug Administration (FDA) this week.
The petition focuses on the labeling requirements for biosimilar products under the 2010 Patient Protection and Affordable Care Act (PPACA), otherwise known as Obamacare. The law established for the first time an approval pathway—the 351(k) pathway—for biosimilar drugs loosely modeled off the 505(j) pathway used to approve generic pharmaceutical drugs.
Biosimilar drugs are highly similar, though not identical, to existing biological products. Due to the complex way in which biological products are manufactured, small differences exist between biosimilars and the products they reference.
One of the biggest struggles faced by FDA regulators so far has been the characterization of those differences, and whether they are clinically meaningful.
But for AbbVie, what regulators deem to be clinically meaningful shouldn't eliminate a patient or doctor's right to know that a product is a biosimilar.
In its Citizen Petition to FDA, the company argues biosimilar products should bear "a clear statement that the product is a biosimilar," and, if necessary, that the product may not be licensed for all indications for which the original drug has obtained approval and may not be interchangeable with the reference product.
At the core of AbbVie's argument is its contention that biosimilars are not generic drug products and therefore should not be treated as such from a labeling policy perspective.
Under the status quo, generic pharmaceutical drugs are labeled more or less the same as the drugs they reference and are not required to bear any statements indicating they are generics or were approved based on fewer data than the reference drug.
To date, FDA has adopted the same approach for biosimilars. In March 2015, FDA approved the US' first biosimilar product, Zarxio (filgrastim-sndz), a copy of Amgen's Neupogen. Zarxio's label does not make any mention of the term "biosimilar," and is nearly identical to the label for Neupogen.
The 'Same Labeling' Approach
For AbbVie, that approach indicates FDA is adopting a "same labeling" approach for biosimilars—an approach that is "legally unsound," AbbVie claims in its Citizen Petition.
"A 'same labeling' approach is flatly inconsistent with the Biologics Price Competition and Innovation Act (BPCIA), which—unlike the Abbreviated New Drug Application (ANDA) provisions in Section 505(j)—includes no 'same labeling' requirement and recognizes that biosimilars are different from their reference products," AbbVie wrote. "Second, a 'same labeling' approach to biosimilars would result in labeling that omits material information necessary for safe and informed prescribing, and would exacerbate, rather than dispel, misconceptions among prescribers regarding biosimilars."
Congress, AbbVie notes, decided "not to borrow the same labeling requirement" from the Hatch-Waxman Act, thereby indicating that it intended for FDA to follow a distinctive approach.
Instead of the traditional "same labeling" approach, AbbVie argues FDA should adopt an approach which recognizes the differences between biosimilars and the products they reference. Those differences are "material" and impact informed prescribing decisions, the petition states, citing a survey of physicians indicating they wanted products to be labeled as a biosimilar.
"Transparency in biosimilar labeling is needed not only to enable informed prescribing, but also to dispel widespread misconceptions about biosimilar products," the petition continues.
"The clearest and simplest facts that should be disclosed in the labeling for any biosimilar pertain to its approval status," AbbVie wrote. "Zarxio was approved, as FDA put it, based on 'less than a full complement of product-specific preclinical and clinical data.'" However, that information is not contained on the labeling for the product, which might influence physician prescribing.
The Pediatric Case for Biosimilar Labeling
Another interesting argument contained within the petition relates to pediatric labeling. AbbVie writes:
In appropriate cases, “pediatric effectiveness can be extrapolated from adequate and well-controlled studies in adults, usually supplemented with other information obtained in pediatric patients, such as pharmacokinetic studies.” When pediatric effectiveness has been extrapolated from studies in adults, the physician labeling for the drug must contain an explicit statement that this has occurred, and it also must include “wording that accurately describes the data submitted.” The same approach is required for biosimilar labeling. Just as prescribers need to be informed when a biological product is approved under special pathways using surrogate endpoint or animal efficacy data, prescribers also should be informed when a biological product has been approved as a biosimilar based on similarly limited data presentations. Just as prescribers need to know when pediatric efficacy was based on extrapolation, they should be informed when biosimilar licensure relied on the extrapolation of indications.
AbbVie adds that the "need for this information will only increase as biosimilars of a single reference product become available from multiple sources," each with their own unique, minor differences relative to the reference product.
The petition goes on to request three actions from FDA:
- A clear statement that the product is a biosimilar, that the biosimilar is licensed for fewer than all the reference product’s conditions of use (if applicable), and that the biosimilar’s licensed conditions of use were based on extrapolation (if applicable);
- A clear statement that FDA has not determined that the biosimilar product is interchangeable with the reference product (if applicable); and
- A concise description of the pertinent data developed to support licensure of the biosimilar, along with information adequate to enable prescribers to distinguish data derived from studies of the biosimilar from data derived from studies of the reference product.
Under the Food and Drug Administration Safety and Innovation Act, FDA has 150 days to respond to AbbVie's petition.
AbbVie Citizen Petition