Targeted cancer therapies refer to drugs and other substances that interfere with cancer cell division, thus blocking the growth and spread of cancer. They focus on cellular and molecular changes specific to cancer, which means they can be both more effective and safer than other types of treatments, such as chemotherapy, which can harm healthy cells in addition to cancer cells.
Most targeted therapy drugs are approved for use as a treatment for specific types of cancer, and others are still being tested in clinical and preclinical trials. They are being studied for use alone or with other targeted therapy drugs, as well as for use in combination with chemotherapy and other cancer treatments.
Many types of targeted therapy focus on proteins involved in cell signaling pathways; by blocking the signals that tell cancer cells to grow and divide uncontrollably, targeted cancer therapies can stop cause the cancer cells to die through a process called apoptosis, in which cells are genetically programmed to essentially self-destruct. Other types of targeted therapy either try to kill cancer cells directly through apoptosis, or indirectly by stimulating the immune system to seek out and destroy cancer cells by delivering toxins directly to those cells. This means that to develop targeted therapies, scientists first must identify good targets that are known to play a role in the growth and survival of cancer cells.
A newer kind of targeted therapy is the use of what are called monoclonal antibodies, in which laboratory-created antibodies—normal components of the immune system that targeted infections—locate and attach themselves to antigens found on cancer cells to mark those cells for destruction by the body’s immune system. Monoclonal antibodies can be used only for cancers whose antigens have been identified.