Study attempts double HIV block by gene transfer

A bold study to make cells resistant to HIV is now recruiting in Sydney. Researchers from the Kirby Institute have paired with the HIV biotech firm, Calimmune, to conduct a small human study of chemotherapy in conjunction with Cal-1.

Cal-1, otherwise known as LVsh5/C46, is basically an inactive virus that has two effects once it gets inside host cells. The first effect is to remove CCR5, the co-receptor found on the surface of white blood cells that helps HIV infect those cells. People who are naturally deficient in CCR5 are resistant to HIV infection. The second effect of Cal-1 is on HIV itself, by blocking some of the critical interactions between the virus and the cell it is trying to infect. The study will measure how well the CAL-1 treatment works, how long the treated cells can be detected in the body of trial participants and whether the treated cells have an effect on HIV levels when participants have a period off treatment.

For the study, participants have both bone-marrow stem cells and CD4+ T cells collected by leukapheresis after being given drugs that encourage bone marrow cells to move into the blood stream. The collected cells are then taken to a specialised laboratory where they are treated with Cal-1 and grown for a short period to increase their number. Participants are then administered a chemotherapy drug to prepare them for the re-infusion of the Cal-1 treated cells. The Cal-1 treated cells are then given as a one-off event and the participants monitored regularly for 6 months. Participants would then be taken off ART to see if the Cal-1 treated cells can control the infection on their own.

Further details of the trial can be found here