Biotech Values

[genisi]

Calimmune's stem cell gene therapy approach for HIV

It is a very different and exciting approach since it tries to render the immune system resistant to HIV rather than directly disrupt the virus itself and has potential for virus eradication.

Questions/Challenges
First, gene transfer with hematopoietic stem cells is challenging plus there's the risk of mutagenesis occurring in host cells by the vector virus.
It is not clear what level of engrafted genetically modified cells will be in the bone marrow without prior complete myeloablation and what percentage of these cells in peripheral blood would be required for clinical benefit in HIV patients. [Also not clear that the apparent cure of the Berlin patient resulted solely from HIV resistant cells transplant. Chemo, immunosuppressive and other drugs could have had an additive effect especially on HIV reservoirs.]
Even if the level of genetic marking of peripheral blood cells is of clinical benefit, will it remain so long-term? Expression of the therapeutic transcript in the peripheral blood might decline over time allowing viral rebound.