Targeted Therapy for Cancer

Targeted Therapy for Cancer

Dr. Alexander Drilon speaking with a patient over telemedicine

Dr. Alexander Drilon, Chief of the Early Drug Development Service, treats many of his patients using targeted therapies. Many of these drugs are taken at home as pills, and Dr. Drilon often meets with patients via telemedicine.

Targeted therapies are cancer treatments designed to target the genetic mutations found in a tumor or the normal genes of an individual patient. It is a personal treatment plan just for the type of cancer you have. The use of targeted therapies is often referred to as “precision medicine” or “precision oncology.”

Lung cancer is a cancer type in which targeted therapies are often the most effective treatment option. There is no one treatment that works for all people who have lung cancer. This is because abnormal cancer cells can be different in each person with lung cancer. Targeted therapies take aim at those differences.

What is targeted therapy?

Cancer is caused by gene changes (mutations or variants). A gene inside a cell can mutate, or change. The cell can start making a protein that also is mutated. This abnormal protein makes cells grow out of control or allows the cancer to spread or become resistant to treatment. Over time, mutations turn normal tissues into a malignant (cancerous) tumor.

Targeted drugs have been designed specifically to block abnormal proteins and stop uncontrolled cell growth. These treatments may shrink or kill tumors.

How does targeted therapy work compared with chemotherapy?

Targeted drugs attack the mutated proteins in cancer cells. Most healthy cells are not affected. Chemotherapy attacks all cells that grow and divide quickly. That includes hair follicles and blood cells.

Many people who take targeted therapies are not likely to lose their hair. They’re also much less likely to have other common side effects of chemotherapy, such as low blood counts.

What are the side effects of targeted therapy?

Common side effects of targeted therapy can include:

  • Fatigue (feeling tired)
  • Gastrointestinal (stomach and intestinal) problems, such as nausea and diarrhea

Some targeted therapy drugs have side effects because the specific proteins they are meant to attack are also found in normal cells. Your MSK care team will talk with you about what side effects to expect. We have a lot of experience dealing with side effects. We can offer treatments that help you feel better, including anti-nausea drugs and integrative medicine treatments.

How do doctors know which targeted therapy drugs to give?

Genetic tests of the tumor cells help doctors tell which gene mutations are driving the cancer’s growth. Most of these mutations will be unique to the tumor you have. But some mutations that are targetable with cancer drugs are inherited from your parents. These mutations can be detected by analyzing normal cells, usually blood cells.

At MSK, we use a number of different tests to detect both kinds of targetable mutations. These tests include MSK-IMPACT® and MSK-ACCESS®. They are most commonly performed using tumor or blood samples.

Your care team can enter the test results into a special database made by MSK, called OncoKB®. It matches you with the best medicine to treat the kind of cancer you have.

The MSK Rapid Diagnosis service helps people who may have cancer get a quick and accurate diagnosis. If tests identify a targeted therapy that is likely to work for you, you can start treatment right away.

What kinds of cancer does targeted therapy treat?

Targeted therapy can help people with many common cancers, including:

Targeted drugs can also help people with cancers that are rarer, including:

Blood cancers such as leukemia and lymphoma can also be treated with targeted therapies.

Some targeted therapies are made to treat certain types of cancer. However, many of them can block proteins that cause cancer, no matter where in your body tumors are located.

Which genetic mutations can be treated with targeted therapy?

Many targeted therapy drugs widely used today were developed through clinical trials (research studies) led by doctors at MSK. Many clinical trials are still ongoing at MSK. Our patients may have access to these drugs before they’re available at most other hospitals.

The most common cancer gene mutations that can be treated with targeted therapy drugs include:

  • BRAF, which is often mutated in melanoma, thyroid cancer, and colorectal cancer.
  • BRCA1 and BRCA2, which are often mutated in breast cancer, ovarian cancer, prostate cancer, and pancreatic cancer.
  • EGFR, which is often mutated in lung cancer.
  • HER2, which may be mutated in breast cancer, stomach cancer, bladder cancer, and lung cancer.
  • IDH1 and IDH2, which are often mutated in acute myeloid leukemia (AML).
  • KIT, which is often mutated in a type of soft tissue sarcoma called gastrointestinal stromal tumor (GIST).
  • KRAS, which is often mutated in lung cancer, colorectal cancer, and pancreatic cancer.
  • PIK3CA, which is often mutated breast cancer and bladder cancer.

Genetic tumor tests such as MSK-IMPACT and MSK-ACCESS can also find gene changes called fusions, which also can be targeted with drugs. These fusions include:

  • BCR-ABL, which is often found in chronic myeloid leukemia (CML).
  • ALK, which is often found in lung cancer.
  • MET, which is often found in lung cancer.
  • NTRK, found across many cancer types in adults and children.
  • RET, which is often found in thyroid and lung cancer.
  • ROS1, which is often found in lung cancer.

Some drugs that target these gene changes can work in a “tumor-agnostic” way. That means they work no matter where in the body the original tumor came from. Gene changes with targeted therapies that are approved to use in a tumor-agnostic way include those that involve BRAF, NTRK, and RET.

What are the different types of targeted therapies?

There are several kinds of targeted therapies for cancer, including:

  • Tyrosine kinase inhibitors. They block specific proteins called tyrosine kinases that help cancers grow. They can treat lung cancer, kidney cancer, and chronic myeloid leukemia.
  • Monoclonal antibodies. These are proteins that are made in the lab to help your immune system fight cancer. They can be used to treat breast cancer, lymphoma, and colorectal cancer. Some newer monoclonal antibodies help deliver radiation more precisely to the tumor.
  • Antibody-drug conjugates. These drugs are made up of an antibody that is attached to a chemotherapy payload. The antibody seeks out the cancer and delivers the chemotherapy to the tumor.
  • Proteasome inhibitors. They block a specific enzyme that helps break down proteins in cells. These drugs can be used for multiple myeloma.
  • Hormone therapies. Several newer hormone therapies are used in people with specific gene mutations.
  • Immunotherapies. Several types of immunotherapies have been shown to work best in people with specific tumor mutations.

How is targeted therapy given?

Targeted therapies can be given in a few ways. You may receive them as:

  • An infusion (through a vein or port)
  • An injection (shot)
  • A pill that you can take at home

Targeted therapies are often given alone, but they can also be given along with other treatments, including chemotherapy, immunotherapy, or radiation therapy.

How long does targeted therapy treatment last?

How long you need to take a targeted therapy depends on a few things. Some targeted therapies are given for a certain period of time, or until there is no sign of cancer. Other targeted therapies are taken for the rest of your life, or until the therapy stops working. Therapies may stop working because of drug resistance.

Drug resistance with targeted therapy

Drug resistance is common with targeted therapies. This is because cancer cells can change and develop new mutations that cause drug resistance.

If the tumor you have becomes resistant to a drug, in many cases your doctor can offer you a different treatment. You also may be able to join a research study, known as a clinical trial. The clinical trial may be designed to test a new targeted therapy drug or combination of drugs. MSK also is doing important research on how to fight drug resistance in targeted therapies.