What is Avastin?

Avastin (Bevacizumab) is one of a newer group of medications called anti-angiogenesis drugs or angiogenesis inhibitors.

When cancer cells spread they need nutrients and oxygen to successfully implant and grow. In order to do this cancers cause the local blood vessels to grow – a process known as angiogenesis. The cancer releases a chemical called Vascular Epidermal Growth Factor – A (VEGF-A) to encourage blood vessel growth. Avastin works by blocking VEGF-A.

Avastin (Bevacizumab) was the first clinically available angiogenesis inhibitor in the US. First approved in 2004 by the U.S. Food and Drug Administration (FDA) for metastatic colon cancer and non-small cell lung cancer, Avastin is currently approved for a number of metastatic cancers.

In 2008, Avastin was approved by the FDA for use in metastatic breast cancer. The decision was highly controversial. The FDA overruled the recommendation of its own advisory committee. Made up of outside advisors, the committee had recommended against the approval by a vote of 5 to 4.

The main reason for the close vote was that the clinical trial did not show that Avastin prolonged the patient’s life or even improved the quality of life. These are two common parameters are often used to measure drug treatment effectiveness.

So, why did they approve it? Avastin did reduce the tumor size and showed an increase in progression free survival time. The tumors began growing again after an average of 11.3 months if the woman took Avastin compared with 5.8 months if she did not.
The FDA is now considering revoking the use of Avastin for metastatic breast cancer and is set to rule by the end of the year.

With the same information available, the National Comprehensive Cancer Network® (NCCN®), a not-for-profit alliance of 21 of the world’s leading cancer centers, dedicated to improving the quality and effectiveness of care provided to patients with cancer recently updated the NCCN Clinical Practice Guidelines for Oncology (NCCN Guidelines™) for Breast Cancer to affirm the recommendation regarding the use of Avastin in the treatment of metastatic breast cancer.
Like any other medication Avastin has side effects. Side effects include High blood pressure, blood clots, heart problems, bowel perforation, and protein in the urine, kidney damage. For many women, the drug is well tolerated.

It is important to remember that Avastin (Bevacizumab) inhibits the growth of blood vessels, which is also part of the body's normal healing. For example, the body grows new blood vessels to heal cuts, and to get around blocked atherosclerotic blood vessels. It is possible that Avastin might interfere.

How is Avastin administered? Avastin is usually given in conjunction with Taxol so the administration schedule will be based on both medications. Avastin is destroyed in the digestive system. It must be given IV. The first treatment takes about 90 minutes and then it is given about every two weeks. Depending on how it’s tolerated the infusion may be decreased to 30-60 minutes. It is possible to get an allergic reaction (<3% of cases). If that is the case the infusion may have to be slowed down over several hours or even stopped. An antihistamine is sometimes given to avoid a reaction. Avastin may affect the bone marrow, kidneys and liver so these are checked on an ongoing basis.

There is so much written about Avastin and metastatic breast cancer. It is important to note that it has been approved for some brain tumors (Glioblastomas), kidney cancers, lung cancers and colorectal cancers. It is also showing promise for some ovarian cancers. In 2010, two trials showed a 27% and 54% increase in progression-free survival. It is being studied for all over the world. Does it work for early breast cancer patients? A large study of 5000 women is underway.
Because Avastin works on new blood vessels, it may work for age-related macular degeneration (AMD) and diabetic retinopathy. Both may be caused by the abnormal growth is caused by VEGF.

Avastin is expensive. Adding Avastin costs about $100,000 a year. In England the cost is nearly £21,000. The National Institute for Health and Clinical Excellence has restricted its use because it extends life rather than providing a cure.

- Dr. Jonathan Herman, MD
www.LearnaboutHBOC.com