A clinical study using gene-edited T cells designed to eradicate persistent HIV infection in patients receiving antiretroviral therapy is expected to start in 2018.
These clinical trials will test the hypothesis that treating patients with their own gene-edited T cells may lead to a sustained increase in T cell counts and eradication of latent HIV reservoirs.
The new study is designed in such a way that T cells from the blood of 20 subjects will have the CCR5 gene “knocked out” via zinc finger nuclease (ZFN) gene editing. The CCR5 gene allows HIV to enter host cells. In this process, ZFN, which are engineered proteins akin to genetic “scissors” is designed to enable targeted editing of genes by creating double-strand breaks in DNA at precise locations identified by researchers.
The newly-edited, “repaired” cell population would be expanded and infused back into the patients. A second set of ten patients will receive an infusion of unmodified T cells.
The study is to be conducted by Case Western Reserve University and Sangamo Therapeutics, Inc with a grant from National Institutes of Health, USA.
Sangamo has completed several earlier phase 1/2 studies evaluating CCR5 edited T cells (known as SB-728-T) in patients. These single-arm studies demonstrated an ability to efficiently knock out the CCR5 gene in T cells by ZFN-driven gene editing and grow the cells ex vivo.