The US Food and Drug Administration (FDA) quietly confirmed last week that it planned to release its long-sought biosimilars labeling guidance document sometime in 2015. But with the agency expected to approve the US' first biosimilar, Sandoz' Zarxio (filgrastim, EP2006), as early as tomorrow (6 March 2015), there's a good chance the biopharmaceutical industry won't have to wait long for the release of that guidance.

Background

At issue is the nomenclature system by which biosimilar products will be named.

Currently, both branded and generic chemical drugs share the same nonproprietary name, also known as its International Nonproprietary Name (INN). For example, both Advil and its generics are both known by the chemical name ibuprofen. This is meant to allow healthcare practitioners to readily assess which drug products are substitutable for one another in clinical practice.

But for biosimilar products, there's a problem. Unlike chemically derived generic drugs, which are supposed to be chemically identical to the drug they reference, it is all but impossible for biosimilar drugs to be identical to the approved biologic they reference. That’s because each product is derived from slightly different cell lines and is produced using slightly different manufacturing processes. While the ultimate products are highly similar, and may even have the same effect on patients, they are nevertheless not identical.

And for some industry and patient groups, those differences are potentially concerning. Those minor differences, they say, could mean biosimilar products cause different adverse events in consumers. If biosimilars share the same INN with their reference biologics, pharmacovigilance—the practice of surveillance after a drug is approved—could be made more difficult for regulators, who might not recognize which product is causing a problem. The groups have argued that each biosimilar should have its own distinct nonproprietary name.

On the opposite side are some public advocacy groups and generics companies, who have argued the issue is a distraction. FDA is the ultimate arbiter of product safety, they say, and attempts to change the names of the products are in part intended to scare or confuse consumers about the quality of new biosimilar drugs.

A third, more mainstream view is that biosimilar products should adopt the nonproprietary name associated with the reference product, but also be accompanied by a short code—ZAR, for example—to allow for easier pharmacovigilance reporting.

Is Guidance Coming This Week?

Everyone, it seems, has weighed in on the issue—with the exception of FDA, that is.

But that could be about to change as early as this week. In August 2014, FDA accepted the first-ever biosimilars application (using the 351(k) pathway established under the AffordableCare Act) for approval in the US. The drug, Sandoz's monoclonal antibody Zarxio, is a biosimilar version of Amgen's Neupogen (filgrastrim).

The drug is somewhat unusual in that it has already been approved by several major global regulators, including the European Medicines Agency, Japan's Pharmaceuticals and Medical Devices Agency (PMDA) and Health Canada. That approval history has given Sandoz a wealth of data with which to placate FDA, which has taken to the drug favorably.

On 7 January 2015, an FDA advisory committee voted 14-0 in favor of approving the drug, all but assuring FDA regulators will do the same.

With FDA set to reach an approval decision on Zarxio on 8 March 2015—the company's biosimilar drug user fee date—it seems likely that the agency will accompany any biosimilar approval decision with the release of its biosimilars labeling guidance.

When asked about the expected timing of the guidance, FDA spokeswoman Sandy Walsh said only that she did not "have any update to share at this time."

Still, it's hard to imagine FDA approving a new product without knowing what it will call the product in its own press release or on the drug's label. So if biosimilar labeling issues are your bread and butter, it might behoove you to pay close attention to FDA's website over the next few days.