A statement by the Food and Drug Administration (FDA) departing commissioner, Scott Gottlieb, reinforced a key aspect of biosimilar naming and provided important updates to the use of four-digit suffixes for biologics and biosimilars.
In his statement, Dr. Gottlieb said, “In January 2017, the FDA published a guidance document in which we sought to balance these concerns by using a distinguishing suffix to the proper names of biological products, including not just biosimilars, but originator products as well. By applying this policy to originator and biosimilar products alike, the FDA sought to advance the goal of patient safety—which the suffixes promote—without creating a misimpression that products with such suffixes are somehow inferior to those without. In addition, the FDA announced in that guidance that the agency was considering the process to retrospectively change the names of biological products already on the market, to begin adding distinguishable suffixes.”
In its updated draft guidance, the FDA announced that it (1) has decided not to add a 4-digit suffix to biologics that have already been approved under the Public Health Service Act, (2) transitioning products, such as growth hormone or insulins, will not be given a 4-digit suffix, (3) the FDA will continue to assign a suffix to biosimilar agents, and (4) any biosimilars that are designated interchangeable will have the usual 4-digit suffix, which will be “devoid of meaning.” In other words, the suffix will not distinguish an agent as interchangeable from one that is not.
The guidance states, “FDA has determined that the core objectives of the naming convention—pharmacovigilance and safe use—can be accomplished by applying the naming convention to biological products 170 at the time they are licensed under section 351 of the PHS Act, and without applying it to licensed biological products that do not contain a suffix in their proper names. This approach is intended to minimize the potential burden for sponsors and the healthcare systems, and to avoid potential confusion for healthcare providers and patients, given that the nonproprietary names of drugs seldom change postapproval.”
The addition of a 4-letter suffix for new biologics is problematic, as the FDA had begun assigning them for at least a couple of years. So far, FDA has given 27 new originator biologics these unique designations, and it seems that to avoid even greater confusion, new biologics will continue to receive the suffixes.
The continuing use of the 4-letter suffix is controversial not only because of the reason stated by Dr. Gottlieb, but also because these designations have not been used to any significant extent in safety reporting. As stated here and in Biosimilar Development, these suffixes have been reported in fewer than 5% of all drug safety reports filed with the FDA to date (but without causing issues as to which biosimilar was associated with an individual report). The updated guidance reaffirms the FDA’s commitment to the use of these suffixes.
Dr. Gottlieb stated, “This framework will help secure pharmacovigilance so that the FDA can effectively monitor all biological products in the post market—originators and biosimilars—and promote patient safety. To aid in adverse event report tracking, originator, biosimilar and interchangeable products will have nonproprietary names that are distinct from each other.”
The problem with this frame of thought is that the suffixes will not achieve a greater level of security in terms of pharmacovigilance in practice. The suffixes are extremely difficult to recall: I know, I find myself today looking for references to nonproprietary names I’ve written about a hundred times. That is precisely why they will not generally be used in drug adverse event reporting.