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April 29, 2009

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HIV gene therapy trial results seen as positive

Feb. 15, 2009
Courtesy Nature research journals
and World Science staff

Re­sults from the first clin­i­cal tri­al of gene ther­a­py in pa­tients in­fected with HIV are re­ported on­line in the re­search jour­nal Na­ture Med­i­cine this week.

The treat­ment appeared to safely increase the num­ber of im­mune sys­tem cells nor­mally at­tacked by the vi­rus, said re­search­ers. But the therapy wasn’t found to sig­nif­i­cantly re­duce the num­ber of HIV vi­rus­es them­selves in pa­tients’ bod­ies.

Gene ther­a­py is a strat­e­gy in­volv­ing in­tro­duc­ing genes in­to pa­tients through var­i­ous means in or­der to re­place de­fec­tive genes or oth­er­wise help the body fight ill­ness.

Gene ther­a­py is an ap­peal­ing op­tion to treat AIDS and the vi­rus re­spon­si­ble for it, HIV, the sci­en­tists who con­ducted the new study pro­pose. That’s be­cause the ther­a­py is seen as po­ten­tially a once-only treat­ment that fights the vi­rus, pre­serves the im­mune sys­tem and avoids life­time an­ti­retro­vi­ral ther­a­py. 

Ronald Mit­suyasu of the Uni­ver­s­ity of Cal­i­for­nia, Los An­ge­les and col­leagues com­plet­ed the first ran­dom­ized, con­trolled gene trans­fer clin­i­cal tri­al in 74 HIV-in­fected adults. About half the pa­tients re­ceived blood stem cells car­ry­ing a a mol­e­cule called OZ1. The mol­e­cule con­tains a gene pre­vi­ously found to pre­vent vi­ral replica­t­ion by tar­get­ing two key HIV pro­teins.

OZ1 caused no ad­verse ef­fects, the in­ves­ti­ga­tors said. Counts of CD4+ lym­pho­cytes—the cell popula­t­ion that is de­plet­ed by HIV—went high­er in the treated pa­tients than in those who had re­ceived a pla­ce­bo treat­ment with no ac­tu­al ther­a­py, the sci­en­tists said. The dif­fer­ences were found by 100 weeks in­to the tri­al.

“This study in­di­cates that cell-delivered gene trans­fer is safe and bi­o­log­ic­ally ac­tive in in­di­vid­u­als with HIV and can be de­vel­oped as a con­ven­tion­al ther­a­peu­tic pro­duc­t,” Mit­suyasu and col­leagues wrote.

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Results from the first clinical trial of gene therapy in patients infected with HIV are reported online in the research journal Nature Medicine this week. The treatment didn’t appear to significantly reduce the number of HIV viruses found in patients’ bloostreams, but did raise the number of immune system cells normally attacked by the virus, and was safe, said researchers. Gene therapy is a strategy involving introducing genes into patients through various means in order to replace defective genes or otherwise help the body fight illness. Gene therapy is an appealing option to treat AIDS and the virus responsible for it, HIV, the scientists who conducted the new study propose. That’s because the therapy could to be a once-only treatment that fights the virus, preserves the immune system and avoids lifetime antiretroviral therapy. Ronald Mitsuyasu of the University of California, Los Angeles and colleagues completed the first randomized, controlled gene transfer clinical trial in 74 HIV-infected adults. About half the patients received blood stem cells carrying a a molecule called OZ1. The molecule contains a gene previously found to prevent viral replication by targeting two key HIV proteins. OZ1 caused no adverse effects, the investigators said. Counts of CD4+ lymphocytes—the cell population that is depleted by HIV—went higher in the treated patients than in those who had received a placebo treatment with no actual therapy, the scientists said. The differences were found by 100 weeks into the trial. “This study indicates that cell-delivered gene transfer is safe and biologically active in individuals with HIV and can be developed as a conventional therapeutic product,” Mitsuyasu and colleagues wrote.