Biological therapies are new medicines that attack cancer cells based on their biological features. They are sometimes called targeted therapies because they target cancer cells rather than attacking all fast-growing cells the way conventional chemotherapy drugs do.
Biological therapies for colorectal cancer include bevacizumab (Avastin), cetuximab (Erbitux), and panitumumab (Vectibix). These drugs are important if you have colorectal cancer that has spread to other parts of your body (advanced or metastatic cancer). Talk with your doctor about whether biological therapies might be an option for you.
In order to grow and spread, tumors need new blood vessels. The process of making new blood vessels is called angiogenesis. Therapies that block the formation of new blood vessels (anti-angiogenesis therapies) “starve” a tumor by limiting its blood supply. One such therapy is bevacizumab.
Cetuximab and Panitumumab
A protein called epidermal growth factor receptor (EGFR) is normally on the surface of cells in your body. This protein may contribute to the growth of colorectal cancer (and other cancers) if there’s too much of it or it’s too active. Drugs that block this protein (anti-EGFR therapies, or EGFR inhibitors) may help stop the growth of colorectal cancer or even shrink it. Two such drugs are approved to treat metastatic colorectal cancer: cetuximab and panitumumab.
Cetuximab and panitumumab are not effective in patients with tumors that have certain mutations to a gene called KRAS. Tests are available to check for these mutations.