By DR. ROBERT EPSTEIN
Personalized medicine has finally arrived and is poised to deliver significant health improvement and healthcare cost savings.
With respect to drug therapy, genetic differences between us can now be easily measured in terms of our ability to break down or metabolize drugs, our ability to ‘ferry boat’ drugs across the gut or brain, or the differences in our targets of the drugs themselves inside our bodies. It is those differences that can make a large difference in beneficial effects, safety or both.
Most pharmaceutical companies today have ramped up their drug development programs to include studies of genetics and drug response, while the FDA has provided a regulatory pathway for the approval of drugs with their companion tests.
The two most prominent near term challenges are (1) incenting comparative effectiveness studies to demonstrate that personalized medicines make a quantifiable improvement in outcomes (i.e. clinical utility) among patients treated in ‘real world’ settings and (2) setting up a platform to both house and take action on this deep and nuanced information since it’s nearly impossible to imagine that clinicians can keep up with the pace of discovery.
CONDITIONS THAT ARE BEING PERSONALIZED
Oncology is one of the leading categories where personalized medicines have been developed and marketed, and recently sales for cancer drugs that are personalized or targeted surpassed the sales for last centuries’ chemotherapies and hormone therapies. For a form of chronic leukemia, we have decreased the five year mortality from 50% to 5% for those with a particular genetic aberration. For breast cancer that follows a particular genetic path, there has been a nearly 50% improvement in outcome rates as a result of targeted therapies. Similar improvements have been seen or will soon be available for genetic sub-groups of colo-rectal and lung cancer, and even malignant melanoma.
Other chronic conditions are finding personalization a reality as well. In cardiovascular disease, genetics is being used to refine the prediction and need for cardiac catheterization, for selecting the right dose of warfarin, for considering whether anti-platelet therapy can work for specific individuals, or for knowing when to more aggressively treat hypercholesterolemia. In virology, genetics has been shown to indicate a safety issue for some patients on an innovative HIV/AIDS drug, while others may not benefit from another drug because the specific pathway the gene uses to enter cells may differ between individuals. A recently approved breakthrough therapy for Hepatitis C has been shown to only work in a particular genetic sub-type of the virus, while the drugs usefulness can be compromised if the patient is a fast metabolizer or takes a drug that causes your liver to quickly metabolize the drug. There is research or personalized medicine approaches for virtually every area of chronic disease today.
CHALLENGES FOR THE FIELD
The challenge is no longer uncovering important genetic knowledge as it relates to drug effectiveness or safety.
It is translating that knowledge into studies that demonstrate using this approach can make a difference in healthcare and outcomes. Additionally studies have demonstrated that physicians do not have requisite knowledge of this emerging field to take advantage of these approaches, so decision support tools are needed as we ‘wire up’ the healthcare system.
This next decade will be distinguished as the decade where personalized medicine gets adopted in everyday healthcare.
ON THE HORIZON
Beyond the study of genetics and drug response, equally exciting advances will bring personalization even further along. Last year, the very first cancer treatment vaccine was launched in this country, in which men with advanced prostate cancer can undergo a procedure where their own immune system (through a series of personalized vaccines with their own cells) is revved up to attack their cancer as a foreign body, resulting in prolongation of life. Gene therapies, while not yet marketed are not far away. For a nine year old boy in a recent gene therapy trial for a form of hereditary blindness, a single injection of the missing gene into his retina resulting in seeing colors, a new ability to read the chalkboard, and the more important outcomes of riding a bicycle and joining Little League baseball. And stem cell treatment studies using your own immature cells – are underway for a wide range of conditions like congestive heart failure and Parkinson’s disease.
These kinds of innovations can only bring more precision to healthcare, improve outcomes and ultimately reduce system costs. The era of one-size fits all will slowly retreat as we better understand and adopt this new knowledge at the bedside. This next decade will be the unfolding of many new areas that may have no market today, but will shape a better future tomorrow.
