CancerQuest | Targeted Therapy

The development of targeted therapy represents an exciting new approach to cancer treatment. A small number of these drugs have already been FDA approved and several others are currently in clinical trials.

Watch the interview with Dr. Alex Adjei.

Perhaps the most promising theme in the development of more specific cancer drugs is the targeting of cancer-specific processes, instead of processes common to all cells. Because these drugs are not directly toxic, and because they only affect cancer cells, they offer the hope of being highly specific with few side effects.⁽¹⁾ The specificity of current drugs does have one drawback. Blocking a single pathway in a cancer cell may be enough to slow it down, but it often does not inhibit the cancer enough to kill it. Therefore, many specific cancer drugs are currently being used together with traditional chemotherapy. The combination of a highly specific cancer drug that is able to attack a tumor's weaknesses, and standard chemotherapy to deliver a powerful attack on the tumor, may prove to be an excellent means of treating cancer. This section will offer some examples of drugs that have been/are being developed to target cancer-specific processes and spare normal cells.

Topics covered in the following pages:

Targeted Therapies vs Conventional Chemotherapy
Kinase Inhibitors
Kinases are enzymes that add phosphate groups onto proteins. Because they control many cellular processes, abnormal activity can result in the development of cancer.
Angiogenesis Inhibitors Angiogenesis, the development of blood vessels, is critical to the growth of almost all types of cancer.
Proteasome Inhibitors Proteasomes are responsible for the destruction of proteins. Inhibition of proteasome activity be used to treat some types of cancer.
Molecular Receptor Blockers Messages are sent between and within cells. Abnormal messaging can lead to cancer and some treatments are designed to interfere with the transmission of these types of messages.
Introduction to Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) DNA serves as a blueprint for the activities in cells. Access to this information is controlled by modifications of the DNA, including addition/removal of small chemical groups (acetyl groups) to the proteins associated with DNA.
Histone Deacetlylase (HDAC) Inhibitors The addition and removal of acetyl groups to histones leads to the creation of pattern of modifications that is critical to the activity of DNA. Manipulation of this 'histone code' can be used to treat cancer.
Antisense Drugs Antisense RNA is able to interfere with the activity of the RNA messages (mRNA) produced when DNA is transcribed.
Ribozymes Ribozymes are RNA molecules with enzymatic (catalytic) activity. This is in contrast with the much better understood protein-based enzymes.
Enzyme Activators Cancer can result in the inactivation of critical enzymes. Some cancer treatments function by turning these inactive enzymes back on.

Know the Flow: Targeted Therapy

You can also view a Cancer Treatment Table containing targeted treatments.