HIV clinical trials in Australia
Researchers in California and Australia have developed a gene therapy called OZ1. This therapy works by making CD4+ T-cells resistant to HIV infection. Results from previous and current clinical trials suggest that OZ1 is safe and has modest effectiveness. However, OZ1 is important in other ways, which we explain later in our report.
About OZ1
Researchers began their project by finding a virus to carry the genes they chose for therapy. The virus they selected was one that caused leukemia in mice. However, they removed the cancer-causing genes and inserted genes that did the following:
- cause CD4+ cells to make an enzyme that cuts up a specific part of HIV’s genetic material; as a result, in cells treated with OZ1, HIV is unable to cause infection.
Study details
Researchers recruited 74 participants whose average profile at the start of the study was as follows:
- 92% male, 8% female
- age – 37 years
- CD4+ count – 700 cells
- viral load – less than 400 copies
- all participants were taking HAART
Researchers randomly assigned participants to one of two groups, as follows:
- OZ1 – 38 volunteers
- placebo – 36 volunteers
Researchers removed blood from the study volunteers and filtered out some bone marrow stem cells, identified as CD34+. They then infused the filtered blood back into participants. CD34+ bone marrow stem cells can develop into any one of a wide range of cells used by the immune system, including CD4+ cells.
The stem cells were collected and cultured and then infected with the weakened mouse virus that carried genes to help make them resist HIV infection. After they were infected, the stem cells were stimulated to produce more CD34+ cells for several days.
These cells were then infused back into participants based on their weight—5 million cells per kg of body weight. For instance, a person who weighed 70 kg would have received 350 million CD34+ cells. Each person received a single infusion of cells. On average, about 54% of the cells infused contained OZ1 genes.
Participants in the placebo group also received CD34+ cell infusions but without protective OZ1 genes.
Participants were highly motivated and able to undertake the 45 visits to study clinics over two years—a requirement of the study. HAART was interrupted during the study to assess the impact of uncontrolled HIV infection on the gene-enhanced cells.
Results
Four weeks after infusion, technicians detected HIV-resistant cells from blood cells in 94% of people in the OZ1 group. One year after the infusion, this figure fell to 12% and two years after the infusion it fell to 7%.
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The Patients Voice in HIV/AIDS Clinical Trial Participation: What motivates the willingness of HIV infected people to take part in HIV/AIDS clinical trials? Book (LAP LAMBERT Academic Publishing)
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BMC Medical Research Methodology at the 35th Annual Conference of the .. — BMC Pediatrics
The conference will focus on issues such as design and analysis of clinical trials, methods in biostatistics and development of clinical prediction models.
Popular Q&A
What is a clinical trial in the context of HIV/AIDS?
'Clinical trial' is often mentioned in HIV/AIDS prevention studies. You will also find mentions of terms like: clinical management of STI (sexually transmitted infecions) and HIV.
A clinical trial is a special kind of research performed to test a new or experiemental drug or therapy on a population.
In terms of HIV, to run a clinical trial, the researchers recruit a group of HIV positive patients. The researchers will randomly assign trial participants to either the experimental therapy or the gold-standard therapy as placebo (contrary to popular belief, placebo is NEVER no treatment in such trials). The randomization process of choice is called double-blind randomized trial, meaning the neither patient nor the research observer knows what the patient is taking …
