The fundamental idea of using the donor's own stem cells is known as an Autologous Stem Cell Transplant and has existed for a while. It is used as therapy for a fair number of blood cancers (e.g. multiple myeloma or a few leukemias).
I think some small number of autologous HSCT recipients require immunosuppressants, but from what I remember the number is very very small. (Allogenic HSCT recipients, who receive cells from a different person, are _much_ more likely to require lifetime immunosuppressants.)
It's super cool that they're able to treat genetic diseases this way!
Using "something" to manipulate the donor cells has also been done for these autologous HSCTs. I know of "CAR T cell therapy", but there are likely others. ( https://www.cancer.gov/about-cancer/treatment/research/car-t... )
I think some small number of autologous HSCT recipients require immunosuppressants, but from what I remember the number is very very small. (Allogenic HSCT recipients, who receive cells from a different person, are _much_ more likely to require lifetime immunosuppressants.)
It's super cool that they're able to treat genetic diseases this way!