What’s Personal about Personalized Dose Management?
Posted by Keith Galloway on Thu, Oct 01, 2009 @ 10:52 AM
Personalized dose management for chemotherapy patients differs from standard dosing in important ways.
Oncologists typically administer doses of chemotherapy drugs based on body surface area (BSA), a standard determined by the height and weight of a patient. They rely on this standard to deliver cancer drugs in doses that are effective without causing severe side effects or toxicity.
Dose management is also influenced by the practice of delivering the maximum dose tolerated by patients. Oncologists engage in this practice in order to achieve and maintain positive response from a given drug. However, oncologists also aim to avoid toxic side effects. These competing goals often lead to either under-dosing or over-dosing of patients, undermining treatment, efficacy and cost effectiveness. That's one reason why oncology has one of the worst efficacy rates in medicine.
The problem with standard chemotherapy dose management based on current standards (BSA) is that it does not take into account key individual differences among cancer patients. These differences include age, health status, genetic makeup, diet, and other medications that might interfere with chemotherapy drugs. Standard dose management also does not reflect the fact that each patient absorbs, metabolizes and eliminates drugs differently. With this standard, blood drug level variations among patients can be greater than ten-fold. See relevant articles.
Personalized dose management, by contrast, is personal because it is customized to the characteristics of individual patients. It is based on simple blood tests that measure the concentration level of a cancer drug in the patient's body. The results of these blood tests allow oncologists to more accurately prescribe doses that are high enough to be therapeutic but low enough to minimize severe side effects and toxicity. Through blood testing, an oncologist can better determine the level of drug in a patient's bloodstream, and adjust drug doses accordingly.
The therapeutic benefits of blood testing are well established. In a published study, patients given doses of the widely used cancer drug 5-fluorouracil based on blood drug level testing (as opposed to standard BSA) received a range of dose adjustments. Compared to patients receiving fixed doses, the patients on adjusted doses achieved nearly double the positive response and greater survival rates. They also enjoyed lower rates of toxic side effects.
Personalized Chemotherapy Management Assays are an example of this more accurate, personalized approach to dose management. Because personalized dose management is based on multiple variables, it is more likely to deliver the appropriate dose to chemotherapy patients. The more effective treatments resulting from this powerful tool increase patient survival rates and quality of life.