What Do Cancer Drug Endings Like — -nib, -mab and -tinib Mean?

-mab stands for monoclonal antibody — a large protein made in a laboratory that is designed to attach to one specific target, such as a protein on the surface of cancer cells or on immune cells. Because they are proteins, monoclonal antibodies are given by intravenous infusion rather than as tablets. The prefix before -mab makes each drug unique: trastuzumab targets HER2 in certain breast and gastric cancers, and pembrolizumab targets PD-1 on immune cells.

-nib stands for kinase inhibitor. Kinases are signalling proteins inside cells that act like switches. In many cancers, one of these switches becomes stuck in the on position and drives uncontrolled cell growth. -nib drugs are small molecules — small enough to enter cells — that block this switch. Most are taken as tablets or capsules rather than infusions. Imatinib, gefitinib, and erlotinib are all kinase inhibitors.

-tinib is a more specific form of -nib. It tells you the drug targets a particular type of kinase called a tyrosine kinase. All -tinib drugs are -nib drugs — all tyrosine kinase inhibitors are kinase inhibitors — but not every -nib drug ends in -tinib. The distinction matters because it says something about which pathway the drug targets, which in turn shapes the expected side effect pattern. Examples of -tinib drugs include osimertinib and erlotinib.

-parib stands for PARP inhibitor. PARP is an enzyme that cancer cells use to repair damage to their DNA. Blocking it causes DNA damage to accumulate inside cancer cells until they can no longer survive. PARP inhibitors are most commonly used in cancers linked to BRCA gene faults — such as certain breast and ovarian cancers — because those cancers rely on PARP-based DNA repair more heavily than others. Examples include olaparib and niraparib.

-zumab is a sub-type of -mab. It is a monoclonal antibody that has been humanised — meaning scientists have modified most of its structure to resemble a human protein while keeping the part that does the targeting. The aim is to reduce the chance your immune system will react against the drug itself. Trastuzumab, which targets HER2, is one example. It works like other monoclonal antibodies and is given by infusion.

It matters for two practical reasons. First, it helps you understand what to watch for: drugs in the same class tend to cause similar side effects. If you know -nib drugs can cause skin rashes and you notice one developing, you are less likely to dismiss it as unrelated. Second, it helps you follow your own treatment. When a doctor mentions a drug by name, knowing its class tells you whether it is a tablet or an infusion and roughly what it is intended to do — which makes clinic conversations more useful.

Yes. The names that follow the WHO suffix system — imatinib, trastuzumab, olaparib — are international non-proprietary names, also called generic names. Branded names, such as Gleevec for imatinib or Herceptin for trastuzumab, are chosen by the manufacturer and do not follow the suffix system. The active ingredient is the same whether you see the brand name or the generic. If you are not sure which name you are looking at, your pharmacist can clarify.

Yes, and this is common. Many treatment plans combine a monoclonal antibody with a kinase inhibitor, or a PARP inhibitor with another agent, because they work on different pathways and can complement each other. Each drug carries its own class-specific side effects, and those can overlap. Your oncologist should explain what each drug in your regimen is intended to do and what to watch for from each one separately — it is reasonable to ask about each drug by name.