Naming of monoclonal antibody drugs

Standard names for biologics, including monoclonal antibodies, use stems. These include prefixes, suffixes, and other indicators that trained people can use to figure out the origin of the drug.

In the US, the United States Adopted Names system is an industry standard that keeps track of drug names and establishes standards in naming conventions. The USAN was established in 1961 and its standards have become accepted in the industry. These names are nonproprietary and not subject to trademark, even if the drug itself is under patent. The World Health Organization maintains an International Nonproprietary Name committee for international standardization of names.

The FDA, although it is represented on the USAN board, maintains a Center for Biologics Evaluation and Research (CBER) which has some say in naming.

Practically, the USAN does not have an iron grip on naming, and the accepted names of drugs emerges through a consensus in the literature among the USAN, the inventor/discoverer of the drug, and the FDA.

The American Medical Association established guidelines for naming of monoclonal antibody drugs.

Generic names for drugs (not brand names) end in the letters “mab” – mab standing for monoclonal antibodies. The AMA rules:

The following letters were approved as product source identifiers:

u = human
o = mouse
a = rat
zu = humanized
e = hamster
i = primate
xi = chimera
axo = rat/mouse
xizu = combination of humanized and chimeric chains

These identifiers are used as infixes preceding the -mab suffix stem, eg:

-umab (human)
-omab (mouse)
-ximab (chimera)
-zumab (humanized)

Chemical compounds have formal names under the International Union of Pure and Applied Chemistry system. If a name has a numeral in it, it is usually a formal chemical name. Monoclonal antibodies are such huge molecules that you never see them referred to as the chemical compound.

Sometimes drugs pick up “trivial names” which are often used by doctors and hospitals and researchers. Another name is the “pharmacy equivalent”, shorthand for complex names.

Commercial entities that develop drugs assign proprietary names to them, which their lawyers usually go through the process of filing trademarks for.