Image for FDA Approves Enzyme that May Help Chemotherapy Patients
Copyright 2013 Natural Standard (
January 2012

FDA Approves Enzyme that May Help Chemotherapy Patients

The U.S. Food and Drug Administration (FDA) approved the use of Voraxaze to treat patients experiencing methotrexate toxicity due to kidney failure.

Methotrexate is a chemotherapy agent commonly used to treat various types of cancer. Chemotherapy drugs are designed to kill cancer cells by interfering with their ability to grow and reproduce. Typically chemotherapy is used to treat cancers that have metastasized (spread) to other parts of the body. Chemotherapy is also used in combination with surgery and/or radiation or to shrink tumors, which helps surgery be easier on the patient and safer. Depending on the type of cancer and its stage of development, chemotherapy can be used to cure cancer, to keep the cancer from spreading, to slow the cancer's growth, to kill cancer cells that may have spread to other parts of the body, or to relieve symptoms caused by cancer. Not all individuals will respond the same way to chemotherapy treatments and some individual's will have more success than others.

Unfortunately, many chemotherapy agents, such as methotrexate, do not specifically attack cancer cells. This means that they not only affect cancer cells but also normal cells in the patients who take them. Consequently, chemotherapy drugs often produce severe side effects, including nausea, vomiting, diarrhea, hair loss, skin problems and damage to blood and immune cells. Patients exposed to prolonged high doses of methotrexate may experience other critical side effects, most notably kidney failure.

The kidneys, a pair of organs located on the left and right side of the abdomen, are an essential component of the urinary tract. The kidneys are responsible for removing toxins, chemicals, and waste products from the blood. These organs also regulate acid concentration and maintain water and electrolyte balance in the body by excreting urine. When kidney failure occurs, the kidneys are damaged beyond repair. Kidney failure is fatal unless treated with a kidney transplant. Symptoms may include altered mental status and advanced uremia (build up of waste in the blood).

To remove high doses of methotrexate from the body, the drug must be absorbed by, broken down by, and eliminated through a process called metabolism. Metabolism is how the body processes materials from outside the body. Metabolism may make a drug inactive or more active or may turn the drug into a form that can be eliminated from the body in the urine or stool. Metabolism occurs primarily in the liver and is performed by proteins called enzymes. After metabolizing a molecule, proteins in the liver then break down the molecule or attach it to "carrier" proteins that allow it to be eliminated from the body.

Voraxaze, manufactured by BTG International, Inc., is specific type of carboxypeptidase enzyme. An enzyme is a protein macromolecule that catalyzes (speeds up) metabolic processes in the body. Enzymes help to digest food, break down toxins, cleanse the blood, strengthen the immune system, build protein into muscle, contract muscles, eliminate carbon dioxide from the lungs and reduce stress on the pancreas and other vital organs. The enzyme Voraxaze is able to speed up the metabolism of methotrexate to a form that is less toxic and that can be eliminated from the body.

One clinical trial showed that Voraxaze, administered into the veins, could rapidly lead to the removal of 95 percent of methotrexate in patients experiencing toxic levels of the chemotherapy agent. Based on the results from this study and other clinical trials, Voraxaze has been approved by the FDA as an orphan class drug, meaning that it can be used in only specific disease populations. Negative side effects of Voraxaze included low blood pressure, headache, nausea, flushing and abnormal sensations in the body.

For more information regarding the effects of chemotherapy and integrative therapies for chemotherapy side effects, please visit Natural Standard's Medical Conditions Database.


  1. Natural Standard: The Authority on Integrative Medicine.
  2. U.S. Food and Drug Administration (FDA).
The information in this brief report is intended for informational purposes only, and is meant to help users better understand health concerns. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions. Copyright 2013 Natural Standard Inc. Commercial distribution or reproduction prohibited.