Angiogenesis Inhibitors Therapy: Questions and Answers 

Key Points 

• Angiogenesis is the formation of new blood vessels and is controlled by 

chemicals in the body (see Question 1). 

• Tumors need blood vessels to grow and spread (see Question 2).

• Angiogenesis inhibitors prevent the formation of new blood vessels so 

that the tumor cannot grow (see Question 3).

• The U.S. Food and Drug Administration (FDA) has approved some 

angiogenesis inhibitors for the treatment of cancer (see Question 4). 

• Angiogenesis inhibitors have fewer side effects than many other cancer 

treatments, but they may only limit the growth of the cancer, not “cure” it 

(see Questions 5, 6, and 7). 

• Researchers continue to test new angiogenesis inhibitors and to 

investigate the way these drugs or chemicals work against different 

cancers (see Question 8). 

1. What is angiogenesis? 

Angiogenesis is the formation of new blood vessels. Angiogenesis is a process controlled 

by certain chemicals produced in the body. Some of these chemicals stimulate cells to 

repair damaged blood vessels or form new ones. Other chemicals, called angiogenesis 

inhibitors, signal the process to stop. 

2. Why is angiogenesis important in cancer? 

Angiogenesis plays an important role in the growth and spread of cancer. New blood 

vessels “feed” the cancer cells with oxygen and nutrients, allowing these cells to grow, 

invade nearby tissue, spread to other parts of the body, and form new colonies of cancer 

cells. 

 

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3. How can angiogenesis be stopped in tumors? 

Because tumors cannot grow or spread without the formation of new blood vessels, 

scientists are trying to find ways to stop angiogenesis. They are studying natural and 

synthetic angiogenesis inhibitors, also called antiangiogenic agents, in the hope that these 

chemicals will prevent or slow down the growth of cancer by blocking the formation of 

new blood vessels. 

4. Are any angiogenesis inhibitors currently being used to treat cancer in humans? 

Yes. The U.S. Food and Drug Administration (FDA) has approved bevacizumab 

(Avastin®) for use with other drugs to treat colorectal cancer that has spread to other 

parts of the body, some non-small cell lung cancers, and some breast cancers that have 

spread to other parts of the body. Bevacizumab was the first angiogenesis inhibitor 

proven to delay tumor growth and, more importantly, extend the lives of patients. 

The FDA has also approved other drugs with antiangiogenic activity as cancer therapies 

for multiple myeloma, mantle cell lymphoma, gastrointestinal stromal tumors (GIST), 

and kidney cancer. 

Researchers are also exploring the use of these drugs to treat other cancers (see 

Question 8). 

5. What are the advantages of angiogenesis inhibitors? 

Angiogenesis inhibitors usually have only mild side effects and are not toxic to most 

healthy cells. Tumors do not seem to develop a resistance to angiogenesis inhibitors, 

even when given over a long period of time, unlike the resistance seen when 

chemotherapy drugs are used. 

Angiogenesis inhibitors seem to help some chemotherapy drugs and radiation therapy 

work more effectively when given in combination. 

6. What are the limitations of angiogenesis inhibitors? 

Angiogenesis inhibitor therapy may not necessarily kill tumors, but instead may keep 

tumors stable. Therefore, this type of therapy may need to be administered over a long 

period. Because angiogenesis is important in wound healing and in reproduction, 

long-term treatment with antiangiogenic agents could cause problems with bleeding, 

blood clotting, heart function, the immune system, and the reproductive system (1). 

 

7. Does angiogenesis inhibitor therapy have any complications or side effects? 

A patient’s immune system may be compromised, making the patient more susceptible to 

infection and causing wounds to heal poorly, if at all. Patients may experience 

reproductive problems, and damage to the fetus is likely if a patient becomes pregnant 
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(gastric) cancer 

or more information about the PDQ Cancer Clinical Trials Registry and other 

while taking the antiangiogenic drug. Heart problems and high blood pressure could be 

made worse, and bleeding or blood clots could increase (1). 

Since angiogenesis inhibitor therapy is still under investigation, all of the possible 

complications and side effects are still unknown. 

8. What does the future hold for angiogenesis inhibitor therapy? 

Other angiogenesis inhibitors are currently being tested in clinical trials (research studies) 

but have not yet been shown to be effective against cancer in humans. If these 

angiogenesis inhibitors are proven to be both safe and effective in treating human cancer, 

they may be approved by the FDA and made available for widespread use. 

The list below includes cancers that are being studied in active phase III treatment 

clinical trials using angiogenesis inhibitors. The clinical trials are in the National Cancer 

Institute’s (NCI) Physician Data Query (PDQ®) Cancer Clinical Trials Registry at 

http://www.cancer.gov/clinicaltrials/search on the Internet. For information about how to 

search the registry, see “Help Using the Basic Clinical Trial Search Form” at 

http://www.cancer.gov/clinicaltrials/basic-search-form-help on the Internet. 

Types of Cancer in Active Phase III Treatment Clinical Trials of Angiogenesis 

Inhibitors: 

• Breast cancer 

• Esophageal cancer 

• Gastrointestinal Stromal Tumors (GIST) 

• Kidney (renal cell) cancer 

• Leukemia 

• Liver (adult primary) cancer 

• Lymphoma 

• Melanoma 

• Multiple myeloma 

• Non-small cell lung cancer (NSCLC) 

• Prostate 

• Stomach 

• Pancreatic cancer 

F

cancer-related information, call NCI’s Cancer Information Service at 

1–800–4–CANCER (1–800–422–6237). 
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Selected Reference 

1. Cohen MH, Gootenberg J, Keegan P, Pazdur R. FDA drug approval summary: 

Bevacizumab plus FOLFOX4 as second-line treatment of colorectal cancer. 

The Oncologist 2007; 12(3):356–361. 

# # # 

Related NCI materials and Web pages: 

• National Cancer Institute Fact Sheet 2.11, Clinical Trials: Questions and Answers 

(http://www.cancer.gov/cancertopics/factsheet/Information/clinical-trials)

• National Cancer Institute Fact Sheet 6.7, Cancer: Questions and Answers

(http://www.cancer.gov/cancertopics/factsheet/Sites-Types/general)

• National Cancer Institute Fact Sheet 7.2, Biological Therapies for Cancer: Questions 

and Answers (http://www.cancer.gov/cancertopics/factsheet/Therapy/biological)

• National Cancer Institute Fact Sheet 7.49, Targeted Cancer Therapies: Questions 

and Answers (http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted)

• What You Need To Know AboutTM Cancer 

(http://www.cancer.gov/cancertopics/wyntk/overview) 

For more help, contact: 

NCI’s Cancer Information Service 

Telephone (toll-free): 1–800–4–CANCER (1–800–422–6237) 

TTY (toll-free): 1–800–332–8615

LiveHelp® online chat: https://cissecure.nci.nih.gov/livehelp/welcome.asp

 

This fact sheet was reviewed on 8/13/08