Big Molecule Watch
February 1, 2016

WHO releases final proposal for naming biological active substances

For the past couple of years, the World Health Organization (“WHO”) has been hard at work devising a system for standardizing the nonproprietary names of biological active substances.  As we reported in an earlier post, the WHO has proposed introducing a Biological Qualifier (“BQ”), a code consisting of four random lower-case consonants, that will be unique to each source of a biological active substance.  In practice, this means that the active substance used in a reference product will have a different BQ than the active used in a biosimilar manufactured by a competitor, and that different biosimilars will have different BQs.  BQs will be assigned by an automated online system maintained by the WHO, and will remain independent from, but used in conjunction with, a substance’s International Nonproprietary Name (INN).  The WHO anticipates that the BQ scheme will work to minimize inadvertent substitution of biological products and aid pharmacovigilance efforts by allowing the industry, pharmacists, doctors and patients to easily differentiate between active ingredients of related products produced by different manufacturers.

The WHO has now released its final proposal and an accompanying FAQ, maintaining its previous BQ scheme and further recommending the addition of a two-digit, numeric “checksum” to the BQ—for example, “bxsh08” or “bx08sh.” The WHO envisions the checksum being incorporated into pharmacy dispensing software, which will provide pharmacists and pharmacovigilance officials the ability to detect errors in the transcription of the BQ, such as erroneously-used or transposed letters.  The checksum will be voluntary, and is designed to be adopted at the discretion of each national regulatory agency.

Last summer, the FDA released draft guidance that proposed a somewhat different naming scheme for biological active substances.  Under the FDA’s proposal, a product’s sponsor (e.g., a BLA, ABLA or IND applicant) would recommend to the FDA a unique, meaningless, four-letter, lower-case suffix to be used in connection with the active substance’s nonproprietary name (e.g., replicamab-cznm or replicamab-hixf).  While the FDA would consider the requested suffix, it would ultimately decide which code to adopt.  The FDA has yet to express an opinion about whether a biosimilar determined to be interchangeable would share the same suffix as the reference product or require a different suffix.  The FDA’s proposal has received quite a bit of criticism, perhaps most notably from the Federal Trade Commission.

It remains to be seen whether the FDA will modify its proposal to better align it with the WHO recommendation.  Given the apparent value in harmonizing the identification and tracking of biological active substances internationally, the FDA may be disinclined to select a naming scheme that could lead to a biological product in the U.S. having a different name than an identical product elsewhere in the world.

Check back here soon for developments in this story.