AIDS Drugs Block XMRV Virus

[From Bloomberg News Service]

A new study from University of Utah and Emory University showed that Merck's Isentress fights the XMRV virus — the virus linked to both prostate cancer and chronic fatigue syndrome. Though much too early to recommend it as a CFS therapy, it is one of many parts of the XMRV/CFS issue that holds promise.

According to researchers, Merck's Isentress fought the XMRV virus more powerfully than 44 other anti-HIV compounds tested against the pathogen in laboratory experiments.

According to a statement from Emory, GlaxoSmithKline's Retrovir and Gilead Sciences's Viread also prevented XMRV from replicating.

The XMRV virus was discovered in 2006 and has since been found in some prostate tumors and in the blood of people with chronic fatigue syndrome. Researchers say its relationship with both diseases is unclear, and European studies last year failed to find the virus in chronic fatigue syndrome patients. Tests of the drugs in patients with XMRV are needed, said Ila Singh, who led the research at the University of Utah's medical school.

"We will need to see the results of clinical trials before these drugs can be used in a clinical setting," Singh said in the statement.

XMRV, like HIV, is a retrovirus that gets incorporated into the genome of the cells it infects. It may trigger cancer by locating in the cell's genetic material next to DNA that controls cell growth, disrupting those genes in a way that allow cells to replicate uncontrollably, Emory said in the statement.

The virus was found in 44 percent of men with the most aggressive form of prostate cancer, Singh found in a study published in September.

XMRV turned up in the blood of two-thirds of a set of tissue samples taken from people with chronic fatigue syndrome and 3.7 percent of a group of healthy individuals, according to separate research published in the journal Science in October.

Isentress is the first in a new class of AIDS medicines that halt HIV by blocking an enzyme called integrase, which the virus uses to insert its genetic material into the nucleus of healthy immune cells.

Merck won U.S. approval in July to sell the drug as an initial therapy for HIV patients. It was previously marketed only to patients who had failed all other therapies.

The research was published in the journal PLoS ONE, a publication of the Public Library of Science, a San Francisco-based nonprofit organization. The study was funded by Emory's Center for AIDS Research and the Department of Veterans Affairs.