Exagamglogene autotemcel
CasgevyRCSB PDB 4CMP · 3D model
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Uses CRISPR molecular scissors to edit a switch in your own stem cells, turning fetal hemoglobin production back on to treat sickle cell disease and beta-thalassemia.
How it works
Doctors first collect blood-forming stem cells from the patient's own body. In the lab, a CRISPR tool cuts a precise spot in a gene called BCL11A, a gene that normally keeps a healthy backup type of hemoglobin switched off. With that switch disrupted, the stem cells start producing fetal hemoglobin again. The edited cells are given back to the patient through an IV infusion after a conditioning treatment that clears space in the bone marrow for them to take hold.
What it’s used for
Approved for people age 2 and older who have severe, recurring sickle cell pain crises, or who have transfusion-dependent beta-thalassemia and need frequent blood transfusions just to stay healthy.
- Mechanism
- CRISPR-Cas9 gene-edited autologous hematopoietic stem cells (BCL11A enhancer disruption)
- Drug class
- CRISPR gene-editing therapy
- Therapeutic area
- Hematology (sickle cell disease / beta-thalassemia)
The first medicine built by directly editing the human genome
Casgevy doesn't work like a normal medicine you keep taking — it's a one-time treatment that directly rewrites a small piece of a patient's own DNA. Doctors take out a patient's bone marrow stem cells, use the gene-editing tool CRISPR to snip out a specific genetic switch, and put the edited cells back in. That switch normally keeps a backup form of hemoglobin turned off after infancy; flipping it back on gives sickle cell patients a working alternative to the sickle-shaped hemoglobin causing their disease. It was the first time the FDA had ever approved a treatment built this way — editing a gene directly, rather than giving a drug that acts on the body from outside.
Pivotal trial
An open-label, single-arm phase 1/2/3 trial in patients 12-35 with severe sickle cell disease, in which 29 of 30 evaluable patients remained free of severe vaso-occlusive crises for at least 12 consecutive months after treatment.