Margarett C Ellison, MD - Avastin - Atlanta, GA
TMH Gynecologic Oncology Specialists - 1775 One Healing Place, Tallahassee, FL 32308   (850) 431-4888

Avastin

How Avastin is Believed to Work: Starving the Tumor Understanding how your treatment can work for you is a big part of what you can do to fight back.
In order to survive, grow, or spread, tumors need a continuous supply of oxygen and nutrients, which they get by creating their own network of blood vessels. This process is called angiogenesis (an'-gee-o-jen'-i-sis).

Avastin is thought to work by blocking a protein released by both normal cells and cancer cells that helps cause angiogenesis. This protein is called VEGF and is produced throughout the life of the tumor. By controlling the growth of blood vessels, Avastin can starve your cancer of the nutrients and oxygen it needs to grow and spread. This is why Avastin is a tumor-starving therapy.

What are the most common side effects of Avastin?
Common side effects that occurred in more than 10% of people who received Avastin for different cancer types, and at least twice the rate of the comparison group, were nosebleeds, headache, high blood pressure, inflammation of the nose, too much protein in the urine, taste change, dry skin, rectal bleeding, tear production disorder, back pain, and inflammation of the skin (exfoliative dermatitis). Across all trials, treatment with Avastin was permanently stopped in 8.4% to 21% of people because of side effects.

Tumor growth without Avastin Tumors get what they need to grow and spread from blood vessels.
  • A tumor continuously sends out a protein called VEGF to nearby blood vessels. This protein causes new blood vessels to grow toward the tumor, a process called angiogenesis
  • Once these new vessels reach the tumor, they provide the supply of blood that brings oxygen and other nutrients to the tumor
Starving the tumor with Avastin With Avastin, tumors can't get the nutrients they need to grow.
  • Avastin may prevent blood vessels from forming by blocking VEGF, a protein that is produced by normal cells and overproduced by cancer cells. In this way, Avastin starves the tumor of what it needs to grow and spread
  • Because it helps prevent blood vessels from forming (angiogenesis), Avastin is a tumor-starving therapy (anti-angiogenic therapy)

Avastin® Effective for Recurrent Ovarian Cancer
Data from two Phase II studies suggest that Avastin® (bevacizumab) is effective and reasonably well tolerated for the treatment of recurrent ovarian cancer. The details of these studies appeared in the November 20, 2007 issue of the Journal of Clinical Oncology.
Avastin is a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF). VEGF appears to play an important role in tumor angiogenesis, and blocking this activity should have an anti-tumor effect. Clinical trials of Avastin have shown activity in a variety of tumors, especially when combined with other agents. However, there have been only three reports of treatment of ovarian cancer with Avastin alone or in combination and these reports involved only a small number of patients (see related news).
A Phase II trial carried out by the Gynecologic Oncology study Group evaluated Avastin in 62 patients with recurrent or refractory ovarian cancer.[1] Two-thirds of patients had received two prior treatment regimens. Forty-two percent of patients were classified as platinum-resistant. All patients were treated with Avastin as a single agent for 21 days.
  • 21% of patients experienced a complete or partial response.
  • The median duration of response was 10 months.
  • 40% of patients survived at least six months without progression.
  • Median progression-free survival was 4.7 months.
  • Median overall survival was 17 months.
Prior responses to chemotherapy, age of the patient, number of prior chemotherapy regimens, or their ability to perform tasks of daily living were not associated with outcomes with treatment with Avastin in terms of cancer progression or death.
The second study involved 44 patients with ovarian cancer who had received one to three prior treatment regimens.[2] Eighty-four percent of these patients were deemed to be platinum-resistant.
  • Partial responses were observed in 16%.
  • Median progression-free survival was 4.4 months
  • Median survival was 10.7 months.
These researchers concluded that Avastin appears to provide anticancer activity and is generally well tolerated for patients with ovarian cancer who have received prior therapy including those who were platinum-resistant. Side effects included hypertension, GI perforation, bleeding and wound healing complications.
Comments: The data from these two studies add significantly to the information available about response rates to Avastin in women with recurrent ovarian cancer.
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