What is targeted therapy?

Targeted therapy is a type of cancer treatment that targets proteins that control how cancer cells grow, divide, and spread. It is the foundation of precision medicine. As researchers learn more about the DNA changes and proteins that drive cancer, they are better able to design treatments that target these proteins.

What are the types of targeted therapy?

Most targeted therapies are either small-molecule drugs or monoclonal antibodies.

Small-molecule drugs are small enough to enter cells easily, so they are used for targets that are inside cells.

Monoclonal antibodies, also known as therapeutic antibodies, are proteins produced in the lab. These proteins are designed to attach to specific targets found on cancer cells. Some monoclonal antibodies mark cancer cells so that they will be better seen and destroyed by the immune system. Other monoclonal antibodies directly stop cancer cells from growing or cause them to self-destruct. Still others carry toxins to cancer cells.

Who is treated with targeted therapy?

For some types of cancer, such as chronic myelogenous leukemia (also known as CML), most people with that cancer will have a target for a certain drug, so they can be treated with that drug. But most of the time, your tumor will need to be tested to see if it contains targets for which there is a drug.

Testing your cancer for targets that could help choose your treatment is called biomarker testing.

You may need to have a biopsy for biomarker testing. A biopsy is a procedure in which your doctor removes a piece of the tumor for testing. There are some risks to having a biopsy. These risks vary depending on the size of the tumor and where it is located. Your doctor will explain the risks of having a biopsy for your type of tumor.

How does targeted therapy work against cancer?

Targeted therapy drugs block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression. They are designed to target and attack cancer cells while causing the least possible harm to normal cells.

These drugs can work in several ways:

  • They can block or turn off chemical signals that tell the cancer cell to grow and divide.
  • They can stop making new blood vessels to feed the cancer cell.
  • They can carry toxins directly to the cancer cell to cause its death.
  • They can stimulate the immune system to recognize and destroy cancer cells.

The exact way that a targeted therapy drug works depends on the molecule that it targets and the type of cancer.

Are there drawbacks to targeted therapy?

While targeted therapy has been a major advance in cancer treatment, it is not without its limitations and potential drawbacks.

One limitation is that not all cancers have well-defined targets for which there are drugs. In some cases, it may be difficult to find a drug that effectively targets the specific genetic or molecular features of a particular cancer.

Additionally, cancer cells can sometimes develop resistance to targeted therapy drugs over time, leading to a recurrence of the disease. This is an area of active research, and new strategies are being developed to overcome resistance.

Finally, like any form of treatment, targeted therapy may have side effects. These can vary depending on the specific drug and individual patient factors. It's important to discuss potential side effects with your healthcare team.

What are the side effects of targeted therapy?

Side effects of targeted therapy can vary depending on the specific drug and individual factors. Common side effects may include:

  • Fatigue
  • Nausea or vomiting
  • Diarrhea or constipation
  • Rash or skin changes
  • Changes in blood pressure
  • Difficulty with wound healing
  • Decreased blood cell counts
  • Liver problems

It's important to discuss potential side effects with your healthcare team, as they can provide specific information about the medication you are receiving and how to manage any side effects that may occur.

What can I expect when having targeted therapy?

When undergoing targeted therapy, you can expect the following:

  • Your healthcare team will closely monitor your progress and any potential side effects.
  • You may need regular blood tests to check for any changes in blood cell counts or liver function.
  • Your treatment plan may be adjusted based on how you respond to the therapy.
  • You may receive targeted therapy either orally (in pill form) or through intravenous (IV) infusion, depending on the specific drug.
  • You may also receive other supportive care to manage side effects and optimize your well-being during treatment.
  • It's important to communicate openly with your healthcare team about any concerns or symptoms you experience during treatment.

Where can I find out about clinical trials of targeted therapy?

You can find information about clinical trials of targeted therapy through various sources:

  • Consult with your healthcare team: They can provide information about ongoing clinical trials that may be suitable for your specific condition.
  • ClinicalTrials.gov: This is a searchable database of privately and publicly funded clinical studies conducted around the world. Visit to search for trials related to targeted therapy.
  • Cancer centers and hospitals: Many specialized cancer centers and hospitals conduct clinical trials. You can inquire about ongoing trials at facilities near you.