Anti-Angiogenesis Treatment -
Mesothelioma Anti-Angiogenesis Chemotherapy
Anti-angiogenesis drugs (synthetic angiogenesis inhibitors) are relatively new types of mesothelioma chemotherapy drugs being researched and tested for the treatment of various cancers, notably malignant mesothelioma. Anti-angiogenesis drugs have proven to be successful in shrinking and killing malignant cells in various animal studies. Although such results have yet to be realized in human studies, it is hoped that use of the drugs will eventually yield similar successes.
Anti-angiogenesis drugs, while not limited to the treatment of malignant mesothelioma, are believed to have the greatest potential in treating the rare disease that has thus far been characterized as incurable.
Angiogenesis is a naturally occurring process through which new blood vessels are formed from pre-existing blood vessels. Blood vessels are the network of arteries, arterioles, venules, capillaries and veins that make up the vascular system. Angiogenesis is essential to the body’s growth and development.
The structural and functional units of all living organisms, cells are often labeled "building blocks of life." Cells require oxygen and nutrients in order to function properly and replicate (mitosis). Angiogenesis is an essential component in cellular growth as it produces the blood vessels through which the required oxygen and nutrients can be fed throughout the body.
The problem with angiogenesis is that it plays a fundamental role in the growth and spread of cancer (metastasis). Mesothelioma cancer cells have abnormal rates of mitosis, dividing in an uncontrollable fashion. Without the aid of angiogenesis, tumor growth would be limited to a size that is typically between one and two mm³. Angiogenesis allows for blood vessel growth into developing tumors, providing them with the oxygen and nutrients required to cater to the uncontrollable growth patterns associated with malignancy.
Anti-angiogenesis drugs obviously function by halting angiogenesis, but what is the biological process at work?
Tumors induce the angiogenesis process through the secretion of various proteins called growth factors. These naturally occurring vascular endothelial growth factors (VEGFs) are found in extremely high levels in most malignant mesothelioma patients. Anti-angiogenesis drugs inhibit the production of VEGF proteins, preventing tumors from secreting growth factors and therefore preventing the formation of new blood vessels into tumors (i.e., larger than one to two mm).
Without the aid of oxygen and nutrients, it is believed that tumors will remain benign, increasing the likelihood of additional treatment (surgery / radiation therapy) success. A number of anti-angiogenesis drugs are currently undergoing a series of clinical trials to determine their effect on the treatment of cancer-stricken patients. Two such drugs are Veglin and Avastin:
- Veglin - Developed by Vasgene Therapeutics Inc., Veglin has had preliminary clinical trial success in reducing VEGF levels without having issues related to toxicity. Phase II of Veglin's clinical trial process is ongoing and involves patients suffering from renal cell carcinoma, mesothelioma, leukemia and lymphoma.
- Avastin - Developed by Genentech Inc., Avastin (bavacizumab) is an anti-angiogenesis drug that is being developed for the treatment of colorectal cancer. Clinical trials have thus far demonstrated that patients who took Avastin in conjunction with additional chemotherapy treatments lived longer on average than patients who only received chemotherapy treatments. Mesothelioma clinical trials are ongoing.
[Page updated August 2009]