This post, Part III, of a three-part series (Part I and Part II) on FDA’s interchangeability draft guidance highlights a number of open issues that stakeholders have identified in their comments to FDA. These include the naming and labeling for interchangeable products as well as the relationship between multiple interchangeable products for the same reference product. Biosimilar makers also wanted FDA to make clear that physician-mediated switching is possible for non-interchangeable biosimilar products even if pharmacy-level substitution is not. A number of patient groups, by contrast, expressed concern that payers were in effect mandating pharmacy-level substitution for non-interchangeable biosimilars by taking innovator products off formularies.
On April 5, the FDA announced the approval of Inflectra, Celltrion and Pfizer’s biosimilar of Johnson & Johnson’s Remicade (infliximab). Inflectra is now the second biosimilar approved for sale in the United States, after Sandoz’s Zarxio. Inflectra’s label and naming reflect the latest FDA guidance.
On Thursday, FDA released draft guidance clarifying its position on labeling biosimilar products. While the guidance addresses some of the concerns raised by physicians and innovator companies, FDA’s guidance largely continues to treat biosimilars like generics for purposes of labeling.
The FDA approved label for the first U.S. biosimilar, Sandoz’s Zarxio, has raised concerns. Zarxio was launched on September 3, 2015 with a label that does not state that the product was approved as a biosimilar to Amgen’s Neupogen and that it has not been determined to be interchangeable to Neupogen. Instead, Zarxio’s label is nearly identical to that of Amgen’s Neupogen and does not identify the information provided by Sandoz to FDA to obtain Zarxio’s approval, including information on immunogenicity specific to Zarxio. AbbVie has supplemented its citizen petition urging FDA not to allow biosimilars to be labeled like generic drugs since biosimilars, unlike generic drugs, are not identical to the originator product and requesting distinct labeling for biosimilars. In briefing U.S. senators on September 17, FDA promised to issue guidance on labeling of biosimilars.
A recent FDA guidance document eliminated biosimilar labeling information that FDA previously viewed as “necessary” for physicians to make prescribing decisions, including whether the biologic is biosimilar to or interchangeable with the reference product. The FDA also approved a label for the first approved US biosimilar that omits this information. The FDA’s actions have drawn criticism from associations of physicians who routinely prescribe biologic medicines and the innovator companies that develop them.