Precision Medicine: Working Toward Custom-Fitted Cures
Tuesday, April 28, 2015
This year may just be the year of precision medicine – a term that’s buzzing on health blogs and in research journals. Precision techniques, proponents say, could change the face of medicine forever.
Simply put, precision medicine is the practice of using genetic information about a person’s disease to treat it. “It’s an approach to aligning clinical care with genomic data that can improve how patients are treated,” says Mark A. Rubin, M.D., professor of pathology and laboratory medicine at Weill Cornell Medical College in New York City.
Precision medicine, Rubin says, moves away from one-size-fits-all disease treatments. “We’re looking to tailor treatment based on genomic data we identify through complex tests that have been developed in recent years.”
Among those betting on the practice is President Barack Obama. During his most recent State of the Union address, Obama announced a $215 million investment in precision medicine for fiscal year 2016.
Sound like gibberish? Here’s what you need to know.
A First Target: Cancer
Obama’s Precision Medicine Initiative aims to “significantly expand efforts in cancer genomics” as a near-term goal, but precision medicine could help patients with all kinds of diseases.Most genomic research today, including Rubin’s, is aimed at cancer treatments.
“There are tremendous applications in other areas beside cancer,” Rubin says. Researchers are mapping genomes of patients with many inherited disorders, including abnormal growths, brain disorders, heart defects and lung defects. “We’re gaining insights in many areas at once right now.”
The Traditional Approach
Outside of precision medicine, medical research is a big-picture game. Clinical trials traditionally focus on a treatment that helps a large percentage of subjects get better. Drugs that work for most patients, but not all, are par for the course; very few treatments work well for everybody, because response to any treatment is highly individual.
Noted neurologist and researcher Dr. Allen Roses explained it like this in a well-known 2003 conference speech. "The vast majority of drugs – more than 90 percent – only work in 30 or 50 percent of the people. I wouldn't say that most drugs don't work. I would say that most drugs work in 30 to 50 percent of people. Drugs out there on the market work, but they don't work in everybody."
Precision medicine starts from the bottom. For cancer patients, precision medicine first benefits those who don’t respond to approved types of surgery, radiation and chemotherapies; that is, those in the minority.
For example, a cancer patient who isn’t responding to treatment can have tissue tested for certain genetic mutations or anomalies. Once doctors identify which genetic variations are present, they can prescribe a drug, usually a chemotherapy drug, known to target that variation.
In a recent article for the science journal Nature, Rubin described a patient with a urinary tract tumor who was successfully treated with a drug typically used to treat breast cancer. Evaluation of a sample of the tumor led doctors to try it. Drugs that target different genes are well-known; it’s which patients are carrying those genes that’s the mystery.
This one-patient-at-a-time approach to medicine is at the heart of the precision movement, but researchers like Rubin say it’s time for widespread use of genomic data, especially in cancer care. Still, there are barriers to making precision medicine a part of everyday clinical practice.
Precision medicine has a long way to go. Start with the fact that DNA contains a lot of information. Analyzing a tissue sample and mapping its genome yields a long and complicated data set, and that’s just for one person. For precision medicine to be widespread, such data needs to be electronic and easily shareable, and we’re just not there yet.
Genomic data is also much harder to process and interpret than traditional lab data. Traditional lab tests include anywhere from one to a few dozen results, data that can be entered manually. “Now we’re talking about much, much more complicated tests with thousands of results,” Rubin says, “and people like me are arguing that they should be incorporated into the patient record, regularly used and followed.”
Right now, hospitals aren’t equipped with the technology or personnel to handle such tasks. They’d have to spend money and time on information systems and training, and they may be unwilling to do so without financial incentive. For now, patients with cancer and other diseases that could be treated with genomic information can try to seek out clinical trials and hope they qualify.
But most patients who could benefit from precision medicine don’t have access to institutions that can help them, and won’t for some time. What the future holds for this exacting science remains to be seen, but there is potential for huge strides. “Now is an exciting time for the field,” Rubin says. “People are already being cured of disease through precision techniques – cures that may not have occurred otherwise.”
This article first appeared in U.S. News and World Reports