What Is Personalized Medicine?

“’Personalized medicine’ refers to the tailoring of medical treatment to the individual characteristics of each patient,” according to the President’s Council of Advisors on Science and Technology report, “’Personalized medicine’ refers to the tailoring of medical treatment to the individual characteristics of each patient,” according to the President’s Council of Advisors on Science and Technology report, Priorities for Personalized Medicine. “It does not literally mean the creation of drugs or medical devices that are unique to a patient, but rather the ability to classify individuals into subpopulations that differ in their susceptibility to a particular disease or their response to a specific treatment. Preventive or therapeutic interventions can then be concentrated on those who will benefit, sparing expense and side effects for those who will not.”

We’re moving from the age of one size fits all medicine to personalized medicine based on the genetic profile of individual patients.

Cancer and personalized medicine
Personalized medicine in cancer has made tremendous strides due to the discovery of biomarkers and their corresponding targeted therapies. Biomarkers are defined by the National Cancer Institute as “A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition.” Biomarkers for a variety of tumor types, such as breast, colorectal and lung cancer, have been identified. These predictive biomarkers can identify the patient subpopulations that are most likely to respond to a specific therapy.

One of the first examples of personalized medicine is the drug Herceptin. “About 30% of patients with breast cancer have a form that over-expresses a protein called HER2, which is not responsive to standard therapy. Herceptin was approved for patients with HER2 positive tumors in 1998 and further research in 2005 showed that it reduced recurrence by 52% in combination with chemotherapy,” reports the Personalized Medicine Coalition (PMC).

The importance of diagnostic tests
To determine whether these new targeted medications will work, the tumors need to be tested for the presence of the biomarker. Diagnostic tests are an essential part of the development of these personalized therapies. I attended a Healthcare Businesswomen’s Association event at Merck where Daniel Winkelman from BioTrends noted, “Approximately 10% of marketed drugs recommend a genetic test for optimal treatment.” The FDA has included as part of therapy labels the applicable branded diagnostic test.

For example, the medication Selzentry targets a specific strain of HIV known as CCR5-tropic. “Selzentry was developed in conjunction with the Trofile™ assay, a molecular diagnostic test that determines if a patient is carrying the CCR5-tropic variation of the virus,” explains PMC.

The future looks bright
Winkelman said that in the past five years there has been a 75% increase in the pharma industry investment in personalized medicine. As targeted therapies are developed for more subpopulations, this investment can be expected to pay off for both industry and patients. What do you think the future holds for personalized medicine?

Image courtesy of Alex Proimos on Flickr (CC BY).