Casgevy: bioethical concerns should not be written off just yet — even though the treatment has been approved

On BioEdge, Dr Patrick Foong and I quickly run through the bioethical perturbations that have come with the relatively rapid approval of Casgevy, the first-ever approved genome-editing therapy that utilises CRISPR/Cas 9. In some ways, it could be said that Casgevy is the first-ever approved genome therapy ‘full-stop’, because other categories of gene therapy have not been understood to create ‘edits’ to the human genome, as such.

For instance, Luxturna (and other AAV therapies) are used to ‘swap out’ mutated genes with ‘healthy’ or unmutated versions of the same. While this may seem like an ‘edit,’ it is also arguably a form of “gene replacement therapy.”

Similarly, forms of therapy using CAR T cells have been characterised as therapies that use cell reprogramming or engineering, rather than cell ‘editing,’ to create their therapeutic effects. This is because the immune cells that are extracted from a patient in a CAR T therapy process, and then reprogrammed to recognise and target cancer cells, is not as much a process by which genes or cells are ‘edited’ as much as one in which they are adapted, ex vivo.

As I have noted previously on Cells and Statutes, one of the most concerning aspects of the process in which Casgevy was approved was that the admitted lack of acceptable data about so-called off-target effects was not deal-breaker: neither for the FDA in the United States nor the MHRA in the United Kingdom.

Closer to home, it will be interesting to see what happens when an evidence dossier lands with the Australian regulator: the TGA. Given the ongoing pivot towards making cell and gene therapies faster to approve, the broader governmental investment in cell and gene therapies (see the 2021 senate inquiry on the future of cell and gene therapy here), and the historical tendency of the TGA to follow the FDA’s decisions, both for scientific and regulatory reasons, I suspect it will be approved without too much agony.