Beyond buzzwords: personalized medicines impact for plan sponsors
Shazia Syed, ACPR. BSc.Phm
Source: Perspective Winter 2013 – by TELUS Health
“Personalized medicines,” “targeted therapy” and “pharmacogenomics” have been buzzwords heavily used in the biopharmaceutical media in the past few years with the seemingly exponential rise in new diagnostic and biomarker technologies developed on a continual basis. As described in this article, this growing field, endowed with an incredible potential to modify the way medicine is practised, also represents possible downstream challenges for plan sponsors.
While not widely available yet, personalized medicine is a paradigm whereby healthcare therapy decisions are customized to an individual patient’s genetic, physiological and/or disease characteristics using refined diagnostic testing for those specific diseases where the technology exists. It is contrary to the conventional “one dose fits all” or “trial and error” approaches that have been widely utilized in the past. This allows physicians to maximize the potential effectiveness of selected therapies by identifying those that have the highest likelihood of a positive response to the drug. Moreover, by selecting for potential responders, the exposure to the drug and any resulting untoward side effects it may (and likely will) cause are mitigated by eliminating the drug as a treatment option for those identified beforehand as not having the appropriate genetic characteristics to respond to it. Whether this results in cost savings is to be determined—however, it does create the potential for downstream increased efficiency for the plan sponsor.
The concept is broad, with applications not only in the initial choice of therapy but also for monitoring and screening patients for appropriateness of preventative therapies. The term “Pharmacogenomics” (PGx) specifically refers to the role that the human genome plays in pharmacology and drug design—providing an awareness into factors such as the ability of the patient to break down or activate a drug in the body. Similarly, the genetic characteristics of a disease itself are encompassed under this term as well, and is the fundamental idea behind the development of “targeted therapies.”
Several applications of the concept of pharmacogenomics with respect to monitoring and screening patients already exist. For example, scientists have determined that variability in the “CYP2C9 and VKORC” genetic profile that patients possess, significantly influences their ability to break down Warfarin, a commonly used blood thinner, ultimately leading to wide variations in response with potentially dangerous implications for patients. Of note, United States (U.S.) estimates show that routine use of genetic tests for Warfarin would reduce the number of serious Warfarin-associated bleeding events that occur annually in the U.S. by between 32,000 and 81,000 and the number of strokes by between 1,700 and 17,000.i
The area of personalized medicine with the greatest attention and growth is the development of targeted therapies, especially within the therapeutic area of oncology. These therapies are being referred to as the “magic bullets” of their respective target populations and are anticipated to revolutionize the market. A 2007 estimate found that targeted oncology products in clinical trials (i.e. not yet approved for use) rose from 10% to greater than 40% in the previous five years, with continuous growth anticipated.i
Targeted therapies specifically refer to drugs or substances that block the growth and spread of diseases, e.g. tumour growth in cancer, by interfering with specific molecules or pathways related to the proliferation of the disease. Research into the characterization of genes that are abnormally expressed in diseased tissue is used to determine targets as well as markers that can be used for diagnostic or prognostic purposes. Table I demonstrates select targeted therapies with a clear gene-drug relationship that are currently available.
With the rapid growth in this treatment paradigm, there is an anticipated rise in the number of high-cost medications with accompanying diagnostic tests. Inevitably, the question of who will be responsible for reimbursing the cost of the accompanying tests comes to light and no clear reimbursement pathway currently exists for companion diagnostics.