It’s from December, but if I have to talk about good news in my field, it would be the constant progress we see in gene therapy. While a number of therapies of this type have already been approved, [Casgevy est la première qui utilise Cas9 pour faire la modification génétique](https://www.npr.org/sections/health-shots/2023/12/08/1217123089/fda-approves-first-gene-editing-treatments-for-human-illness). Gene therapy has been in constant progress since the 2000s, and makes it possible to treat diseases that were until then absolutely beyond the reach of medicine, which could at best treat symptoms. A milestone for me, since I had the pleasure of speaking with Michele De Luca, is the total cure of a 7 year old boy suffering from junctional epidermolysis bullosa, a genetic disease causing massive and constant inflammation of everything the epidermis. Very painful, until the inflammation causes cancer, and then it becomes fatal. Researchers and surgeons succeeded in modifying skin stem cells, and replacing the boy’s entire epidermis, with his own skin, but healthy this time ([source académique](https://www.nature.com/articles/nature24487), [presse](https://www.npr.org/2017/11/08/562647401/genetically-altered-skin-saves-a-boy-dying-of-a-rare-disease)). Spinal muscular atrophy is also now treatable via Zolgensma. Casgevy works by reactivating, in patients’ blood stem cells, the fetal hemoglobin gene, which will take over from the patients’ malformed adult hemoglobin. A very classic method, known in mice since the 2000s. Here, the idea in particular is to modify the site to which BCLA11 attaches to repress the expression of fetal hemoglobin. No more site, no more BCLA11 attaching, no more repression. Despite everything, Casgevy points out the same problems as the rest of gene therapies. The promise of Cas9 is, above all, the ease with which one can make a modification just about anywhere. And indeed, in my lab, I could probably make the modification in question for less than €1000 (salary included). The therapy itself will be sold for 2 million. Part of the difference is because there is a world of difference between doing the modification on the fly, and cultivating & validating blood stem cells in sufficient quantities. The other part is the cost of intellectual property, and the fact that a lot of gene therapy addresses rare diseases. Fewer patients mean fewer people to repay the considerable investment of clinical trials (and then profit). But given that 95% of the research that was necessary to understand the mechanism of BCLA11, to suspect that it could be an avenue for therapy, etc., has been public, we sometimes wonder why private entities then profit .
https://old.reddit.com/r/france/comments/1c65n5g/première_thérapie_génique_basée_sur_crisprcas9/
Posted by Prae_