2 verifications about CRISPR CRISPR ×
“Ex vivo CRISPR-based therapies for sickle cell disease typically require myeloablative conditioning with busulfan before reinfusion of edited hematopoietic stem cells.”
Current evidence shows busulfan-based myeloablation is the standard preparative step before reinfusion in ex vivo CRISPR sickle cell therapies. FDA labeling for Casgevy and published trial reports describe busulfan conditioning, and broader reviews say busulfan remains the usual regimen across these autologous ex vivo approaches. Alternative conditioning strategies exist in research, but they are not yet typical practice.
“Many CRISPR-based sickle cell disease clinical trials primarily edit the BCL11A gene or its enhancer to reactivate fetal hemoglobin rather than directly repairing the HBB mutation.”
The evidence shows that BCL11A or its erythroid enhancer has been a central target in multiple CRISPR sickle cell trials, including the approach behind Casgevy/exa-cel. These programs aim to reactivate fetal hemoglobin rather than directly fix the HBB sickle mutation. Other editing strategies exist, but they do not undermine the claim’s use of “many.”