Despite nearly universal opposition from both biosimilar makers and innovator companies, FDA has issued final guidance adopting its controversial August 2015 proposal for naming biologics. Under the guidance adopted by FDA, the nonproprietary name of a biologic will consist of the core nonproprietary name of the originator product plus a meaningless but distinguishable suffix of four lowercase letters unique to each product.

As an illustration, FDA explains that an originator and a biosimilar sharing the core name “replicamab” might be assigned the nonproprietary names “replicamab-cznm” and “replicamab-hjxf,” respectively. The last three biosimilars approved by FDA, Amgen’s Amjevita (adalimumab-atto), Sandoz’s Erelzi (etanercept-szzs), and Celltrion and Pfizer’s Inflectra (infliximab-dyyb) have all followed the meaningless but distinguishable naming convention.

Under the final guidance, the proposed suffix should:

• Be unique

• Be devoid of meaning

• Be four lowercase letters of which at least three are distinct

• Be nonproprietary

• Be attached to the core name with a hyphen

• Be free of legal barriers that would restrict its usage

The proposed suffix should not:

• Be false or misleading, such as by making misrepresentations with respect to safety or

efficacy

• Include numerals and other symbols aside from the hyphen attaching the suffix to the

core name

• Include abbreviations commonly used in clinical practice in a manner that may lead the

suffix to be misinterpreted as another element on the prescription or order

• Contain or suggest any drug substance name or core name

• Look similar to or be capable of being mistaken for the name of a currently marketed

product (e.g., should not increase the risk of confusion or medical errors with the product

and/or other products in the clinical setting)

• Look similar to or otherwise connote the name of the license holder

• Be too similar to any other FDA-designated nonproprietary name suffix

In comments concerning the draft guidance, most stakeholders expressed a preference for meaningful and therefore memorable suffixes instead of meaningless ones. For instance, Amgen, an innovator and biosimilar maker, argued for suffixes tied to the name of the sponsor, which it stated would “help prescribers and patients with product identification, thereby avoiding inadvertent substitution and fostering accurate attribution of adverse events.” Many commenters voiced concern that meaningless suffixes could lead to a variety of errors and ultimately risk public safety. Nevertheless, FDA is moving forward with its naming scheme, concluding that a system of meaningless but distinguishable suffixes best balances its goals of “maximizing the success of biosimilar products” and “ensuring the safety of patients receiving biological products.”

FDA is continuing to consider the suffix format for interchangeable products.