1. Monoclonal Antibodies

These are lab-made proteins that specifically bind to antigens on the surface of cancer cells. Once attached, they can:

Block growth signals

Deliver toxins or radioactive substances directly to cancer cells

Mark cancer cells for destruction by the immune system
Example: Trastuzumab (Herceptin) for HER2-positive breast cancer.

2. Tyrosine Kinase Inhibitors (TKIs)

TKIs are small-molecule drugs that block enzymes (tyrosine kinases) involved in cell signaling, growth, and division. By interfering with these pathways, they stop cancer cells from multiplying.
Example: Imatinib (Gleevec) for chronic myeloid leukemia.

3. Angiogenesis Inhibitors

These drugs block the formation of new blood vessels (angiogenesis) that supply tumours with oxygen and nutrients. Without this blood supply, tumour growth is slowed or stopped.
Example: Bevacizumab (Avastin) is used in various solid tumors.

4. Proteasome Inhibitors

They disrupt the function of proteasomes, which are cellular complexes that break down unneeded proteins. This leads to cancer cell death.
Example: Bortezomib is used in multiple myeloma.

5. PARP Inhibitors

These inhibit PARP enzymes that help repair damaged DNA. Cancer cells with existing DNA repair issues (like BRCA mutations) are more likely to die when PARP is blocked.
Example: Olaparib for ovarian and breast cancer.

6. mTOR Inhibitors

mTOR is a protein that helps control cell growth. Inhibiting it can prevent cancer cells from growing and dividing.
Example: Everolimus for breast and kidney cancer.

Targeted Therapy: Types, Advantages and Side Effects