FDA Reiterates Decision on Suffixes in Biosimilar Naming

A Federal Register notice from FDA addressed comments on the guidance on Proprietary Naming of Biological Products and the agency’s decision to require applicants to submit up to ten proposed, four-letter suffixes for biological products licensed under the Public Health Service (PHS) Act. In the notice, FDA reiterated its earlier decision to require applicants to “propose a suffix of four lowercase letters for use as the distinguishing identifier included in the proper name designated by FDA at the time of licensure for biological products under the PHS Act.”

Responses to FDA’s guidance, which was initially released in August 2015, indicated that applicants were concerned about the time burden that may encompass coming up with, and providing analysis for, the proposed suffixes. Many respondents commented that FDA’s estimate of two hours per suffix (six hours for three suffixes and analysis) was considerably low. One commenter indicated it would exceed 720 hours per suffix to complete an analysis and submission, totaling 2160 hours. FDA said that while it found this estimate “rather high” it revised its estimate to account for “burden associated with creating and submitting up to 10 proposed suffixes for designation.”

In addition to the time consideration, FDA also mentioned commentary on suffix meaning. Several respondents indicated the importance of selecting a suffix that would help improve pharmacovigilance, enhance safety, and effectively identify a biological product. By comparison, others voiced support for a random suffix, or no suffix at all. FDA did not indicate its preference, and it is still unclear how biosimilar makers should select suffixes.

This lack of clarity triggered responses from organizations including the Biosimilars Forum, which admitted to finding the guidance’s current language confusing. The Biosimilars Forum also indicated that it did not support the suggestion of a random four-letter suffix. Instead, the Forum suggested the implementation of a suffix that is “unique to the original product license holder, and will be affixed to all biological products developed by that license holder.” The Forum also commented on the potential need to change biosimilar labeling information throughout a products lifecycle, specifically mentioning pregnancy and lactation requirements. The Forum indicates that it may not be feasible for biosimilars to adhere to the pregnancy and lactation final labeling rule, since the biosimilar maker does not have access to reference product data. 

Source: FDA, Biosimilars Forum