Pharmacogenetics – The future of “Personalized Medicine”

European Americans are ten to forty times more likely than African Americans to get a very aggressive type of skin cancer called Melanoma. People of Asian descent are more likely to have the inability to process alcohol efficiently – exposing them to more toxicity. People of Northern European descent have a predisposition for Type 1 diabetes. High blood pressure is twice as common in African Americans than in the rest of the American population. Native Americans have higher rates of tuberculosis, pneumonia, and influenza. I’ll stop there; the list is rather large.

I mention the above statistics to bring the point home for the need for more targeted or “personalized” drugs within the Pharma industry. A “one size fit all” approach for every disease/disorder simply does not aim for maximum effectiveness. Clearly the above example and more importantly common sense points to the fact that every human being is not like every other human being when it comes to appropriate medical treatment and disease prevention. Individuals have different germlines based on many factors within the evolutionary track of a specific population.

To some this may mean the end to “Blockbuster” drugs that could be prescribed to anyone who falls under a certain ailment. At the same time it may also mean capturing a higher percentage of a subgroup such as Asians or African Americans with diabetes; this would also be side-by-side with a higher success rate. But a change in drug development philosophy will come with a change in processes ranging from compound identification to clinical trials. Depending on the overall impact of these changes, they may or may not be welcomed. Whether Pharma companies will welcome the strategy of developing drugs toward specific groups or try to hold on to the past “one size fits all” model has yet to be seen.

The heart failure drug BiDil was approved by the FDA in 2005 and was the first medication marketed for a specific racial group; in this case African Americans. Although it must be mentioned, BiDil was never meant to be a drug targeted for a particular racial group; it just ended up that way after trials of the drug on the general population of severe heart failure patients showed a benefit only in African Americans. Since its approval, it has disappointed on the market with only $12.1 million in sales for 2006. A drug is considered a “Blockbuster” usually when the $1 billion barrier is broken. Further, BiDil has reached only about 1% of the 750,000 African Americans in the US with congestive heart failure. In January of 2008, NitroMed, the drug’s manufacturer, announced plans to end all promotional activities of the drug.

Unfortunately, some may see BiDil as a case of failure for “personalized medicine.” The fact is there were many factors that could have contributed to the outcome such as marketing, coverage restrictions under the Medicare drug benefit, and the availability of a generic alternative to name a few. Also, if all is judged off the expectations set by the multi-billion dollar sales of past “Blockbuster” drugs then, sure, it may not be a success under that definition. Of course, the monetary concerns of Pharma companies are not something to be brushed aside because there is a high cost to innovation and drug development.

My take on this is that science and the facts show that “personalized medicine” is needed. This may not be true for every disease or disorder, but it certainly is the case for quite a handful. Pharmacogenetics, or the study of how genetic variation can affect pharmaceutical treatment, will aid in developing a new more effective class of drugs. Personalized drugs, cost reduction, lean clinical trials, and a higher success rate is the way to a successful future.