February 18, 2009
A study of gene therapy to treat HIV has shown that the treatment is safe and somewhat beneficial -- a "major advance" in efforts to combat the virus -- researchers said in a study published recently in the journal Nature Medicine, AFP/Google.com reports. According to the researchers, the study -- which was headed by Ronald Mitsuyasu of the University of California-Los Angeles -- confirms that this avenue of gene therapy in HIV research is a valid approach (AFP/Google.com, 2/15). The study involved 74 HIV-positive people, half of whom received blood stem cells that included a molecule, called OZ1, which is designed to block HIV from replicating by targeting two key proteins (BBC News, 2/16). The other half were given a placebo. The study aimed to determine whether the stem cells would survive the body's immune system and if this would curb the replication of HIV. The researchers found that after 48 weeks, there was no statistical difference between the two groups. However, after 100 weeks, the group that received the RNA enzyme gene had higher levels of CD4+ T cells and low HIV viral loads. The study also showed that the new blood stem cells depleted over time -- although DNA tests showing that the modified cells were present in 94% of the gene group at four weeks, this fell to 12% by week 48 and 7% by week 100. According to the researchers, the study's results showed the treatment was "safe" and modestly effective. Mitsuyasu said that instead of putting the technique through to a Phase III trial, the team plans to modify the technique and introduce new tests on a smaller group of participants. He said the study "gives some hope" to the gene therapy approach as a treatment for HIV and other diseases, such as cancer, adding, "It's a positive finding for the field and should move the field forward" (AFP/Google.com, 2/15).
Mitsuyasu said that the treatment is "not yet as effective or as complete as current antiretroviral therapy in controlling HIV," although the recent study "did show proof" that using a single gene in an HIV-positive patient's own blood cells could reduce the spread of the virus. Jo Robinson of the HIV/AIDS organization Terrence Higgins Trust said, "Gene therapy is an exciting area which aims to create a one off treatment for HIV, avoiding the need for people to take daily medication," adding that the therapy is in its "early days in research terms, so we're a long way from something like this being on the market." Robinson said that the new study "has shown some promising results, which definitely warrant further investigation." Keith Alcorn of the U.K.-based HIV information service NAM added that although the study's results are "very modest," the researchers showed "enough of an effect for us to be hopeful that a gene therapy approach to HIV treatment might eventually deliver effective treatments for the disease" (BBC News, 2/16).
An abstract of the study is available online.