On August 27, 2015, the Food and Drug Administration (FDA) released draft guidance on nonproprietary naming of biological products. The agency’s draft guidance proposes that the core nonproprietary name for originator biological products, related biological products, and biosimilar products be appended with a unique, four-letter suffix designated by the FDA in order to distinguish each product and minimize inadvertent substitution of products that are not interchangeable.

A New Naming Convention

The proposed framework for the naming convention includes the nonproprietary name — otherwise known as the proper name — of the originator biological product along with a designated four-letter suffix attached to the core name with a hyphen. Importantly, a related, biosimilar, or interchangeable product will share a core name with the originator biological product, but will also include a distinct four-letter suffix. This convention will indicate a relationship among the products while highlighting the unique identification of each product.

For example, two products sharing the core name of replicamab might have the following nonproprietary names:

• replicamab-cznm

• replicamab-hixf

The FDA has not yet decided whether the nonproprietary name for an interchangeable product should also include a unique four-letter suffix or whether it should be assigned the same proper name and suffix as its reference product. The draft guidance notes that the agency is seeking comment on these alternative approaches.

Which Products Are Covered?

The FDA’s proposed naming convention would apply both prospectively and retrospectively to biological products licensed under sections 351(a) and 351(k) of the Public Health Service Act, although the agency is still considering how the convention should apply to interchangeable products. As indicated in the draft guidance, the FDA believes that the designated suffix is warranted for both newly and previously licensed biological products in order to advance a number of goals, including (1) ensuring that patients only receive the biological products intended to be prescribed to them, (2) facilitating manufacturer-specific pharmacovigilance, (3) encouraging the routine use of designated suffixes, and (4) avoiding any inaccurate perceptions of the safety and effectiveness of biological products based on their path to licensure.

Designating a Suffix

Applicants and current license holders may propose their own suffix, which should consist of four lowercase letters devoid of any meaning. Proposed suffixes should not be promotional, include any abbreviations commonly used in clinical practice, contain or suggest the name of any drug substance, or look too similar to the name of a currently marketed product or another product’s suffix designation. The FDA will evaluate a proposed suffix and notify the applicant of its determination. Given the FDA’s previous selection of “sndz” for Sandoz’s Zarxio (filgrastim-sndz), it will be interesting to see the approach and development of these suffixes.

Comments and suggestions on the draft guidance are due by October 27, 2015, at www.regulations.gov. (Docket No. FDA-2013-D-1543).

Relatedly, the FDA issued a proposed rule to be published in the Federal Register on August 28, 2015, that would designate “the official names and the proper names” for six biological products that qualify as either a reference product, a related biological product, or a biosimilar product. As the agency explains, its proposed action with respect to the six products covered by the rule is meant to encourage the routine usage of designated suffixes.