Cancer cells grow in an uncontrolled fashion. Tykerb works inside the cancer cell by interfering with certain proteins, called kinases, that can stimulate this uncontrolled growth.
Genes are like instruction manuals that tell each cell in the body how to grow, what kind of cell become, and how to behave. They do this by ordering the cell to make special proteins that cause a certain activity -- like cell growth, rest, or repair.
Some cancer cells have abnormalities in genes that tell the cell how much and how fast to grow. Sometimes the cancer cells have too many copies of these genes with abnormalities. When there are too many copies of these genes, doctors refer to it as “overexpression.” With some forms of gene overexpression, cancer cells will make too many of the proteins that control cell growth and division, causing the cancer to grow and spread.
Some breast cancer cells make (overexpress) too many copies of a particular gene known as HER2. The HER2 gene makes a protein called known as a HER2 receptor. HER2 receptors are like ears, or antennae, on the surface of all cells. Breast cancer cells that overexpress the HER2 gene make too many HER2 receptor proteins and are said to be HER2-positive.
Inside a HER2-positive breast cancer cell, HER2 receptors use protein signals, called kinases, to cause the cell to grown and divide abnormally. Kinases control how much energy the cells have to grow and multiply. Breast cancer cells that overexpress HER2 can have too much kinase activity, so the cancer cells grow too much, too fast.
Tykerb works by interfering with HER2-related kinases inside the cell, limiting the amount of energy breast cancer cells have to grow and multiply. By limiting the amount of energy, Tykerb can slow or stop the growth of breast cancer.
Tykerb is a targeted therapy, but unlike Herceptin (chemical name: trastuzumab) and Avastin (chemical name: bevacizumab) it is not an immune targeted therapy. Immune targeted therapies are versions of naturally occurring antibodies that work like the antibodies made by our immune systems. Tykerb is a chemical compound, not an antibody.