What is Bevacizumab?

Bevacizumab is a generic prescription medication that is taken intravenously. Doctors typically prescribe it for the treatment of certain types of cancer, as well as for a rare condition that affects the eyes known as retinal angiomatous proliferation. The drug generally attacks cancer cells by not allowing them to grow new blood vessels, thereby cutting off their food supply.

Cancer occurs when cells within a particular part of the body begin to grow uncontrollably, forming masses called tumors. To continue growth, cancer cells require nutrients. Like all cells, cancer receives its required oxygen and minerals from blood delivered through tiny tubes called blood vessels.

Once bevacizumab enters the bloodstream, it seeks out specific proteins on cancer cells, known as vascular endothelial growth factor A. These proteins serve as a vital building block for blood vessels. Once bevacizumab binds to the vascular endothelial growth factor A, cancer cells become unable to produce blood vessels. Since the drug functions in this way, it has received the name angiogenesis inhibitor — angio means blood vessel, while genesis means origin.

Without the ability to grow new blood vessels, cancer cells receive less blood and, in turn, fewer nutrients. In this way, bevacizumab slows the growth rate of cancer cells. This helps prevent the disease from spreading to other parts of the body. In some cases, cancer cells eventually die because of the effects of the drug.

Bevacizumab is a monoclonal antibody — a bio-engineered chemical that functions similarly to immune cells by affecting only one particular type of cell in the body. In this case, the cells target only those that contain growth factor A. By contrast, chemotherapy drugs do not have the ability to distinguish one type of cell from the next. Instead, they exert their actions on healthy cells as well as cancer cells.

Not all types of cancer respond to bevacizumab. Doctors commonly prescribe the drug for the treatment of colon or rectal cancer that has metastasized or spread to other parts of the body. It is also effective as a treatment for a type of lung cancer called non-squamous, non-small cell as well as for a type of brain tumor known as glioblastoma. Though less common, the medication also works against some forms of kidney and breast cancers.

Patients may also receive bevacizumab for the treatment of retinal angiomatous proliferation. Retinal proliferation occurs when blood vessels grow on the surface of the retina — the part of the eye that is primarily responsible for vision. The condition results in a gradual loss of vision, which the drug can slow or prevent by impeding the growth of blood vessels.

Scientists continue to study the effects of bevacizumab on other types of cancers and medical conditions. Other types of monoclonal antibody medications are in development as well in the hopes of providing new methods to treat disease. While not a cure-all, these drugs typically need the guidance of a qualified medical professional.