On June 2, AbbVie, Inc. submitted a citizen petition requesting that FDA require the approved prescription drug labeling for biological products licensed under the Public Health Service Act (PHSA) include:
(1) 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, and that the biosimilar's licensed conditions of use were based on extrapolation;
(2) A clear statement that FDA has not determined that the biosimilar product is interchangeable with the reference product; and
(3) 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.
AbbVie contends this information in biosimilar labeling is necessary to "enable rational and informed prescribing decision regarding these complex products, to avoid potentially unsafe substitution of biosimilars and reference products, and to combat widespread misconceptions among prescribes about biosimilars and their relationship to reference products." The citizen petition further asserts without this information biosimilar labeling will not reflect licensure provisions in the Biologics Price Competition and Innovation Act of 2009 (BPCIA) and will be "materially misleading in violation" of Food, Drug, and Cosmetic Act (FDCA) and FDA regulations. AbbVie also alleges a violation of the Administrative Procedure Act (APA).
The BPCIA created a two-tiered abbreviated licensure pathway for follow-on biological products. It can be licensed under BPCIA if it is "biosimilar" to a "reference product" as defined in the PHSA. Alternatively, a biosimilar can be deemed "interchangeable" with a reference product if certain heightened showings required by the PHSA have been made. As noted in the petition, on March 6, 2015, FDA approved the first biosimilar product in the United States (Zarxio®). AbbVie claims that the labeling for this product mimics the approved labeling for Neupogen (which has not been found to be interchangeable with Zarxio), "which suggests that FDA has decided to apply the 'same labeling' requirement found in FDCA … for small-molecule generic drugs to biosimilars licensed under … the PHSA." AbbVie also argues public materials from FDA's review of Zarxio confirms that the agency followed this "same labeling" approach.
AbbVie argues it would be legally unsound for FDA to adopt this approach to biosimilars for three reasons. First, the company asserts this is inconsistent with BPCIA which includes no "same labeling" requirement and "recognizes that biosimilars are different from their reference products." Second, this labeling approach to biosimilars would result in misconceptions among prescribers regarding biosimilars. Third, FDA did not follow APA requirements to explain its decision to abandon the approach outlined in its Draft Scientific Guidance, which stated the extent of labeling for biosimilars.
The petition describes the characterizing feature of the BPCIA pathway as one that deems biosimilars to be unique from their referents. AbbVie notes that Congress established distinct approval pathway for biosimilars, and that pathway includes "no analogue to the same labeling requirement that exists for small-molecule generic drugs under the ANDA provisions of the FDCA." This, AbbVie contends, distinguishes the BPCIA from the FDCA's ANDA provisions. By using the same labeling requirements for both ANDA products and biosimilars, it lacks legal foundation and "would conflict with the novel licensing scheme established by the BPCIA."
Additionally, AbbVie's petition argues, the "same labeling" requirement to biosimilars leads to misleading labeling in violation of the FDCA and FDA regulations. As described by a number of groups in a letter to FDA leadership, "the level of education that still needs to take place surrounding biosimilars, some physicians may mistakenly view that an identical label implies that a biosimilar is interchangeable with the reference product and has approval for all of the same indications—which we know may not be the case for many biosimilars." This runs contrary to stated goals in FDA regulations, that drug labeling should affirmatively present safety and effectiveness information needed for informed prescribing or rebut misconceptions.
FDA regulations further state that "the basis for approval of the drug product, including the extent of the product's benefits," should be included in labeling to "provide practitioners with more accurate and specific information about a drug's efficacy that could help them to make informed prescribing decisions." The petition infers from this that FDA regulations thus provide the basis for a drug's approval to be disclosed in its approved physician labeling. Omissions in Zarxio labels result in "materially misleading biosimilar labeling," running starkly in contrast to this stated policy.
Interestingly, the petition also cites non-American jurisdictions which require biosimilar labeling to include information at issue in AbbVie's petition. For example, guidance from Health Canada states that unlike "generic pharmaceutical drugs, the sponsor of a [biosimilar] will not be able to utilize the [labeling] of the reference biologic drug in its entirety as that of its own product." Labeling for the biosimilar will include statements indicating the product is a biosimilar, information regarding the indications approved for use, and data on which the decision for market approval was made. In the petition, AbbVie asserts that similar information "should be provided to prescribers in the United States" because physicians "need and want to know whether a product is a biosimilar, the scope of its approval, and whether the approval was based on extrapolation." AbbVie points out that FDA proposed to require labeling statements like this in 2012 in a guidance stating that biosimilar labeling "should include all the information necessary for a health professional to make prescribing decisions."
The petition continues, arguing that prescribers need to know whether a biosimilar is, in fact, interchangeable with the reference product. Without this information, prescribers may not be able to tell "whether the biosimilar is a potential substitute for the reference product". Such an omission "misleadingly suggests that the biosimilar could be substituted for its referent, just like a generic drug, which increases the risk of inappropriate product switching." Furthermore, AbbVie contends that prescribers need biosimilar-specific data and also need to know whether data discussed in labeling are from the biosimilar itself, or from the reference product, to avoid omitting important safety and efficacy information.
AbbVie's citizen petition challenges important considerations surrounding the labeling of biosimilars. The labeling protocol the FDA used was the same one they typically use for generic drugs.
Another problem with the labeling, this one for biosimilar manufacturers in the Zarxio label is that none of the clinical or analytical data that supported the finding of bio similarity to the reference product is included in the label, which will put biosimilars at a disadvantage when they go to detail the product to physicians, pharmacists and payers. Much of what they would talk about for a branded drug will be considered off label promotion.
The company believes appropriate labeling on these drugs are critical to informed prescribing and avoiding potentially unsafe substitution of biosimiliars and reference products. As pointed out in the Wall Street Journal, researchers expect biosimilars to sell at discounts to their original reference drugs of between 20% and 30%. If that proves accurate, first movers on biosimilars, such as Pfizer and Novartis, are poised to benefit. This would come at the expense of those companies that have blockbuster drugs facing loss of exclusivity but have not invested in biosimilars, such as AbbVie and Roche. Thus, we can expect these fights to continue as more biosimilars are on their way. We will continue to monitor this issue closely.