Targeted therapy, also called biologic therapy, uses the body's immune system or hormonal system to fight breast cancer cells. That does less harm to healthy cells, so the side effects aren’t usually as bad as from better-known treatments like chemotherapy.
One type of targeted therapy uses antibodies to kill cancer cells or block them from growing. Antibodies are a part of the immune system made by special white blood cells. They can be made in a lab and given as medicine.
Pertuzumab (Perjeta) is another antibody that treats HER2-positive breast cancer. Doctors use it along with docetaxel and trastuzumab. Pertuzumab may be harmful to a fetus, so women who are pregnant shouldn’t take it.
Another medication, ado-trastuzumab emtansine (Kadcyla), combines the antibody in trastuzumab with a chemotherapy drug. Doctors give it to people with HER2-positive, advanced breast cancer who were already treated with trastuzumab.
One possible drawback of antibody treatment is that you generally need to get it as a shot.
Lapatinib(Tykerb) is an example of a small-molecule drug that you can take in a pill. It's used together with chemotherapy to treat some advanced cases of HER2-positive breast cancer. Doctors often use it when other cancer medications haven't worked for someone.