The protocol of the trial has been modified to increase the number of stem cells that engraft in a patient’s bone marrow.
In the upcoming trial, which is expected to get underway shortly, Enzo’s HGTV43 gene construct will be used to transfer three antisense genes designed to interfere with the growth of HIV-1 into blood stem cells.
These cells are expected to replicate and differentiate within the body of the HIV-1 infected individual to produce CD4+ T-cells, the main target of infection by HIV-1. The novel aspect of the current study is to increase the percentage of CD4+ cells that contain the anti-HIV-1 antisense genes with a protocol designed to partially reduce the patient’s blood stem cells before infusion of the engineered cells.
The trial is intended to determine whether this procedure will create a supply of HIV-1 resistant CD4+ cells large enough to materially defer the disease progression of these HIV-1 infected individuals into AIDS
A previous phase I study demonstrated the safety of the procedure and showed that the engineered stem cells were able to survive long term in vivo and to produce a low number of CD4+ cell progeny containing functioning antisense genes.
“We look forward to moving into this next phase of the trial, the goal of which is to increase the proportion of immune cells containing anti-HIV-1 antisense genes, and possibly block the progressive loss of immune competence that characterizes the progression into AIDS,” commented Dr Dean Engelhardt, executive vice president of Enzo. “This approach could add a much needed option in the management of HIV infection.”