Could be first step toward personalized medicine, experts say
WEDNESDAY, Feb. 6 (HealthDay News) -- New research suggests that an expensive blood test could help a small minority of HIV patients discover whether they should avoid a common AIDS drug that can sometimes cause serious side effects.
The test detects sensitivity to the medication abacavir by checking to see if a patient's genetic makeup is linked to poor reactions to the medicine.
"This is very important news in relation to the great hopes from the work with the Human Genome Project," said Magnus Ingelman-Sundberg, a professor at Karolinska Institutet in Sweden, who wrote a commentary about the research. The genome project aims to analyze the genetic blueprint of humans.
At issue is the AIDS drug abacavir, also known by the brand name Ziagen, which is found in compound drugs known as Trizivir and Epzicom. The drug is known as a nucleoside reverse transcriptase inhibitor and works by preventing the AIDS virus from going through the motions of multiplying.
About 8 percent of patients suffer from hypersensitivity to the drug, said study author Simon Mallal, a researcher at Murdoch University & Royal Perth Hospital in Australia. His report on the results is published in the Feb. 7 issue of the New England Journal of Medicine. The problems typically occur within the first six weeks that patients use the drug, he added.
According to the study, the side effects include fever, rash, gastrointestinal symptoms and other problems.
By testing patients for a genetic trait that was found in 5.6 percent of 1,956 female and male patients, the researchers found they could spot potential cases of sensitivity to abacavir.
The test's use could allow doctors to do a better job of personalizing drugs for individual patients, Mallal noted.
The study was funded by GlaxoSmithKline, the maker of the drug, and several researchers reported receiving funding from the company. Mallal is the sole shareholder of a company that is trying to get a patent for a test for the genetic trait.
Rowena Johnston, vice president of research for amfAR, The Foundation For AIDS Research, said it remains to be seen if the test will be cost-effective.
According to Mallal, the test could potentially cost $100 to $150 in the United States. Ingelman-Sundberg, the Swedish researcher, put the cost at about $200.
"On the more favorable side, we certainly need more effective ways to predict who will tolerate which drugs or combinations better or worse," Johnston said. Patients who have side effects on drugs often don't bother to take them, which can make their bodies develop immunity to medications, she said.
"This might be one start towards building a battery of tests that could predict who will do well on which antiretrovirals," she said. "But I think more research could provide tools that are easy to implement and might ultimately help patients achieve high adherence so they can take full advantage of the ability of antiretroviral therapy to prolong life."
Learn more about abacavir from the National Institutes of Health.
SOURCES: Magnus Ingelman-Sundberg, Ph.D., professor, Karolinska Institutet, Stockholm, Sweden; Simon Mallal, M.B., Murdoch University & Royal Perth Hospital, Perth, Australia; Rowena Johnston, Ph.D., vice president, research, The Foundation For AIDS Research, New York City; Feb. 7, 2008, New England Journal of Medicine
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