There's a lot of excitement in the biomedical community about the potential for "personalized medicine"--the tailoring of a patient's treatment to reflect his or her individual biology. The best known prospect is selecting between drug or dosing alternatives based on a DNA tests that may predict how a person will respond, but there are other ways to improve individual outcomes as well. There have been a few specific commercial drugs with genetic tests so far, notably erbitux and warfarin, with mixed results. Nonetheless, I have no doubt that the researchers are sincere in their hopes for improved treatment.
Unfortunately, the history of the pharmaceutical industry offers less basis for optimism. I've been reading the disturbing book Our Daily Meds, by former New York Times reporter Melody Peterson (Amazon, B&N). This is just one of several recent books documenting the cynical manipulation of the prescription-drug process by Big Pharma in service of their own profits. The list of manipulation techniques is long, including inventing new diseases to be treated by their newest drugs, evading requirements for full disclosure of side effects by advertising by hiring celebrity promoters and funding patient groups focused on individual diseases, flooding the scientific literature with ghost-written articles that favor their drug, encouraging prescriptions for off-label uses, creation and marketing of useless "me too" drugs, and much more.
The take-home message is that the pharmaceutical companies rarely limit their sales to patients who would truly benefit from them, which is what personalized medicine really requires. In fact, the companies have taken many opportunities to extend their drugs to diseases in which studies have shown little benefit, to downplay or deny side effects, and to open their markets to include new. unstudied populations. They also tolerate the fact that many recipients don't benefit from the drug they pay for.
Personalized medicine would demand the opposite, shrinking the market for each drug to those who actually respond. At the same time, the complexity and expense of clinical trials that subdivide the patients into subgroups will be much higher. It seems unrealistic to expect our current commercial and regulatory system to rise to this challenge without some major changes.