Friday, March 13, 2009
The closest most of us get to personalized medicine is having a personal relationship with a doctor. But in the future, medicine itself may be personal. Customized medicine is a growing trend that's being driven by knowledge of the human genome. KPBS Health reporter Tom Fudge says a lot of this kind of research is being done in San Diego.
(Photo: The SOLiD machine is a DNA sequencing system. Courtesy of Life Technologies )
There's a break in the Oncology Symposium at UC San Diego's Moores Cancer center. Dozens of cancer doctors and researchers drink coffee and eat croissants. The lectures and presentations can be tough to follow. Lots of talk about somatic mutations and EGR receptors. But it all gets down to stopping a deadly disease.
One of the conferees is John Mendelsohn, who founded the UCSD Cancer Center. He says the future of cancer treatment lies in knowing that different patients require different treatments.
"If you reduce cholestral, you help heart disease, and one size fits all. But in cancer there are probably three of four hundred different genes that can be problematic. And in any one cancer it might be half a dozen of them out of that list of three or four hundred that are causing the cancer," says Mendelsohn.
Knowledge of genetics is key to matching the treatment to the patient. Kip Miller is president of genetic systems for Life Technologies, a Carlsbad biotech company that manufactures a gene mapping device. He says, for instance, one very common gene mutation can render a popular, and expensive colon cancer drug called herbatux entirely ineffective.
"So if you can get that information right up front and see if you have the k-raz mutation, you can save your insurance company from having to pay that," he says. "You can save yourself six weeks so you can undergo some other theraputic regimen, and you can save that drug, which is precious because it is very difficult to make, for someone else who will actually benefit from it."
The gene sequencing machine, made by Life Technologies, is called Solid 3.0. Miller says it's reduced the cost of mapping one person's genome to $10,000. Of course, you need to have access to a Solid machine first, and the machine costs half a million. Still, it's a huge jump in affordability. Ten years ago mapping a human genome cost nearly $3 billion. The hope is to eventually reduce the cost of mapping your genome, with its six billion coding letters, to $1,000.
Dr. Eric Topol is the chief academic officer for Scripps Health. He says it's already pretty easy to test people for a single gene mutation that makes you resistant or responsive to certain drugs. But he says we have very limited knowledge of the multitude of tiny genetic differences among us that can have an impact on treatment. He says the human genome is so diverse that it remains a mystery.
"Only five people have been fully sequenced, to date, and published," says Topol. "We have such limited knowledge. Until we get thousands of people sequenced, and make heads or tails of those more uncommon, rare, low-frequency coding letter changes, then it becomes useful information."
Back at the cancer symposium one topic of discussion is the possibility of sequencing the genomes, not of people, but of the cancers itself.
David Bentley is chief scientist at a San Diego-based biotech company called Illumina. He says scientists have already mapped the genome of a melanoma tumor. Unfortunately, like people, not all melanomas are the same, and many more sequences need to be done.
Benley says the genetic puzzle of cancer must come together, so we can abandon ineffective treatments for ones that really work.
"So while we have something like 140 approved, FDA-approved anti-cancer drugs, many of them may be administered without full knowledge of the enemy within. And we can do a great deal more to understand that," says Benley.
The future of cancer and other disease treatments could go something like this. You go to the doctor, you get a lab test to check for gene abnormalities, then you receive a drug cocktail that's designed for you. John Mendelsohn says it's not common practice today, and it will be expensive. But he thinks personalized medicine will eventually save lives and save money.
Tom Fudge, KPBS News.