Naming of Cancer Drugs

Pharmaceutical companies sell their products under brand names or trade names. The companies register them as trademarks. This website prefers to call medicines by their generic names. The generic names are the ones see in the scientific literature. For instance, cisplatin is the generic name of a common chemotherapy agent, while the drug is sold under the name Platinol. Cisplatin isn’t a scientific name by the method of how today’s chemists name compounds though. That would be is‐Dichlorodiammineplatinum. There are also alphanumerical designations in other classification schemes: the Chemical Abstracts Service (CAS registry number 0015663-27-1), the Anatomical Therapeutic Chemical classification (L01XA01), and the chemical formula (Cl2H6N2Pt)

The field of medicinal chemistry has systems for naming medicines that help knowledgeable people understand something about the medicine – that something can be the medicine’s mode of action in the body, its origin, or the type of illness it affects.  Having said that, if you look at how we classify chemotherapy drugs – the taxonomy of ctx medicines – there is not complete consistency.

Monoclonal antibodies

Medicines made by a monoclonal antibody process have names ending with “mab”. The letters immediately before mab are about the antibody’s origin. This is not referring to the organism that was used to synthesize the antibody, but to the species on which the structure of antibody was based (eg, to look like an antibody observed in mice).  “U” means human origin. “Zu” means humanized antibodies. “O” means a murine (mouse) origin. “Xi’’ refers to chimeric MABs, part human and part other species. “A” means rat origin, “e” means hamster origin. “I’ means non-human primate.  Sometimes you even see xizu which refers to a combination of humanized and chimeric chains in the molecular structure.

The third-to-last syllable is assigned based on the biological target researchers had in mind for the drug.  “Tu” and “tum” are intended for cancer. “Li” is for the immune system and “ci” is for drugs that affect the circulatory system.  Note that these designations don’t necessarily dictate what the medicine is used for in clinical practice; they were assigned early in the development of the drug.

For instance, bevacizumab has the “mab” ending which indicates it is a monoclonal antibody; it has “zu” which shows it is a humanized antibody; it has “ci” which indicates it targets the cardiovascular system. Bevacizumab is given to cancer patients, but it works by stopping growth of blood vessels.

When biosimilars – drugs that act like but are not exactly like the original biologic medicine – became prevalent, the FDA decided it could not let them be referred to as the same name as the original as they were not exactly the same.  So the regulators referred to the new drugs under the name of the original but appended with a dash and four random letters.  Hence biosimilars to bevacizumab are bevacizumab-awwb and bevacizumab-bvzr.  The four letters have no particular meaning.  The FDA instituted this practice in 2015.  In 2017 it started appending a dash and four letters to even new biologic medicines.  So dostarlimab-gxly, a new drug approved in 2021, gets four letters even though it is an original drug.

Angiogenesis inhibitors

Drugs ending in -anib are angiogenesis inhibitors and you can see this in examples like Pazopanib and Sorafenib although some drugs that work through antiangiogenesis have other names.  For instance Bevacizumab and Ramucirumab have names denoting their monoclonal antibody origin while Thalidomide has a name from decades ago.

Drug names that end in -ib

-tinib refers to tyrosine kinase inhibitors

-zomib drugs are proteasome inhibitors

-ciclib means cyclin-dependent kinase inhibitors

-rafenib means BRAF kinase inhibitors

-parib means PARP inhibitors

-degib means Hedgehog pathway inhibitors

-lisib means P13K inhibitors

-denib means IDH inhibitors

Others (a selection)

Drugs that end in –kin are analogues to interleukin.

-rubicin refers to anthracycline antibiotics.  Other antioiotics used in cancer treatment end in -mycin.

Aromatase inhibitors have names ending in -mustane or -rozole.

-lutamide refer to antiandrogens.

-bulin designates mitotic inhibitors or tubulin binders.

-trexed designates antineoplastic thymidylate synthetase inhibitors.

mTor inhibitors have names ending in -limus.  HDAC inhibitors have names ending in -stat, except for Romidepsin which has a name from its discovery in nature.

Other types of names

AN – Approved name (UK)
CAS – Chemical Abstract Service
JAN – Japanese Accepted Name
NSC – Number assigned to medicine when an entity is submitted to the National Cancer Institute
OS – Official Synonym
Rec.INN – Recommended International Nonproprietary Name (World Health Organization)
USAN – United States Adopted Name

Note the United States Adopted Name Council is part of the American Medical Association.  Names it assigns have almost always been adopted as the generic name for new medicines in the US in the past couple of decades.