What is precision or personalized medicine?
Would a teenage boy buy the same clothes as his grandmother? Probably not. But when they get sick, they’re likely to receive the same medical treatment, despite their many differences. And so will everyone else.
That’s because even the world’s best scientists and doctors don’t fully understand yet how different people develop disease and respond to treatments. The result is a "one-size-fits-all" approach to medicine that is based on broad population averages. This traditional practice often misses its mark because each person’s genetic makeup is slightly different from everyone else’s, often in very important ways that affect health.
The advent of precision medicine is moving us closer to more precise, predictable and powerful health care that is customized for the individual patient. Our growing understanding of genetics and genomics — and how they drive health, disease and drug responses in each person — is enabling doctors to provide better disease prevention, more accurate diagnoses, safer drug prescriptions and more effective treatments for the many diseases and conditions that diminish our health.
Tailoring health care to each person’s unique genetic makeup – that’s the promising idea behind precision medicine, also variously known as individualized medicine, personalized medicine or genomic medicine.
What are the benefits of precision medicine?
Throughout history, the practice of medicine has largely been reactive. Even today, we usually must wait until the onset of diseases and then try to treat or cure them. And because we don’t fully understand the genetic and environmental factors that cause major diseases such as cancer, Alzheimer’s and diabetes, our efforts to treat these diseases are often imprecise, unpredictable and ineffective.
The drugs and treatments we devise are tested on broad populations and are prescribed using statistical averages. Consequently, they work for some patients but not for many others, due to genetic differences among the population. On average, any given prescription drug now on the market only works for half of those who take it.
Personalized medicine, because it is based on each patient’s unique genetic makeup, is beginning to overcome the limitations of traditional medicine. Increasingly it is allowing health care providers to:
- shift the emphasis in medicine from reaction to prevention
- predict susceptibility to disease
- improve disease detection
- preempt disease progression
- customize disease-prevention strategies
- prescribe more effective drugs
- avoid prescribing drugs with predictable side effects
- reduce the time, cost, and failure rate of pharmaceutical clinical trials
- eliminate trial-and-error inefficiencies that inflate health care costs and undermine patient care.
Personalized Medicine Is Impacting Patient Care in Many Diseases. For Example...
…in Breast Cancer:
One of the earliest and most common examples of personalized medicine came in trastuzumab. About 30% of patients with breast cancer have a form that over-expresses a protein called HER2, which is not responsive to standard therapy. Trastuzumab was approved for patients with HER2 positive tumors in 1998 and further research in 2005 showed that it reduced recurrence by 52% in combination with chemotherapy.
…in Melanoma:
BRAF is the human gene responsible for the production of a protein called B-Raf, which is involved in sending signals inside cells to direct cell growth, and shown to be mutated in cancers. In 2011, a drug called vemurafenib, a B-Raf protein inhibitor, and the companion BRAF V600E Mutation Test were approved for the treatment of late stage melanoma. Vemurafenib only works in the treatment of patients whose cancer tests positive for the V600E BRAF mutation. Around 60% of patients with melanoma have a BRAF mutation, and approximately 90% of those are the BRAF V600E mutation.
…in Cardiovascular Disease:
Prior to the development of a gene expression profiling test to identify heart transplant recipients’ probability of rejecting a transplanted organ, the primary method for managing heart transplant rejection was the invasive technique of endomyocardial biopsy – a heart biopsy. Today, a genetic diagnostic test is performed on a blood sample, providing a non-invasive test to help manage the care of patients post-transplant. New research suggests that ongoing testing may be useful in longer-term patient management by predicting risk of rejection and guiding more tailored immunosuppressive drug regimes.
Learn more about Personalized Medicine:
Personalized Medicine: How your Genome can improve Healthcare