In general, drugs often work in only half of the people who take them.  In addition, billions are spent to treat adverse drug reactions and other complications.  The personalized medicine approach is to elucidate the differences between patients who respond to a drug and those who don’t, and to treat only those who will benefit, thus enhancing drug safety.  Fear of lost market share has been given as 1 reason for the slow acceptance of this approach.  Pharmacy benefit managers (PBMs; e.g., Medco and CVS Caremark) may be tweaking the business model.  PBMs anticipate making money by selling personalized medical services to employers, who are willing to pay them higher fees for improved health outcomes and lower prescription costs.   Both employers and PBMs expect genetic testing will increase the percentage of patients using cheaper generic drugs, thus increasing profits.

The business case for the personalized medicine approach is expected to strengthen as more genes and drug responses are linked.  Warfarin and Plavix (blood thinners) and tamoxifen (a breast cancer drug) were suggested as current candidates for this approach.  Additionally, results from any given genetic test are generally applicable to many drugs.  For example, the same variation that determines the response to Plavix can help determine how the anti-anxiety drug Valium, heartburn drugs like Nexium, and the antidepressant Celexa should be used.

Although “the blockbuster mentality is still in place, drugmakers are coming around” asserts Dr. Bruce Littman of Translational Medicine Associates.  Furthermore, regulatory agencies may refuse to approve and payers may decline to reimburse future drugs that can’t be directed to the right patients.  According to Richard Schatzberg of Generation Health, drugmakers predict a future business model where they can secure all of the smaller market of appropriate patients.  In theory, this approach should reduce adverse events and help to differentiate drugs based primarily on efficacy.

Source:  Business Week