Mabs
The number of monoclonal antibodies with clinical uses is bewildering. I recently counted about 50, from abciximab to zolimomab aritox. Their names seem bewildering too, but are actually easy to decipher.
Modern international non-proprietary drug names have two parts. The suffix, or stem, tells you what group the drug belongs to, ideally chosen to reflect its pharmacological action. For instance, -vastatin denotes HMG Co-A reductase inhibitors (-stat- often being used for enzyme inhibitors); -olol denotes b–blockers (but beware stanozolol); and -mycins are antibiotics. The prefix is chosen at will. It might reflect the structure or source of the drug (e.g. diclofenac, virginiamycin), the inventor's love of opera or the cinema (e.g. mimimycin, rifampicin; see BMJ 1999; 319: 972), or just whimsy.
Now the monoclonal antibodies have a prefix and three substems. All, with one exception, end in -mab, for monoclonal antibody. The penultimate syllable (or substem) indicates the animal source and the prepenultimate syllable the target (Table 1). And the prefix (one or two syllables) is up for grabs.
Table 1.
The components of the names of monoclonal antibodies.
| Prepenultimate syllable (general target) | Prepenultimate syllable (tumour target) | Penultimate syllable (animal source) |
|---|---|---|
| -ba(c)- = bacterium | -co(l)- = colon | -a- = rat |
| -ci(r)- = cardiovascular | -go(t)- = gonad (testis) | -e- = hamster |
| -le(s)- = infectious lesions | -go(v)- = gonad (ovary) | -i- = primate |
| -li(m)- = immunomodulation | -ma(r)- = mammary | -o- = mouse |
| -vi(r)- = virus | -me(l)- = melanoma | -u- = human |
| -pr(o)- = prostate | -abo- = rat–mouse hybrid | |
| -tu(m)- = tumour | -xi- = chimerica | |
| (unspecified) | -zu- = humaniseda |
aDon't ask.
Finally, if the antibody is conjugated to a toxin an extra word is added; aritox, for example, denotes the A chain of ricin.
Let's try it. Abciximab can be parsed as follows: ab-ci-xi-mab. The -xi- denotes a chimeric antibody and the -ci- a cardiovascular target. Whoever named it was sleeping on the job — the target is actually the platelet. What about trastuzumab (Herceptin)? Well that's a humanised antibody (-zu-mab) that targets an unspecified tumour (-tu-). If you wanted to show that it targets the breast specifically, you could call it tramazumab.
Now play the game yourself. Imagine a chimeric monoclonal that targets syphilitic gummata; the stem would be -le-xi-mab. If it had six active domains, you might be tempted to call it sexileximab. I would.