Casgevy (exagamglogene autotemcel)
An approved treatment for Sickle Cell Disease and Thalassemia.
The same compound appears under different names depending on the context. Here is how to identify Exagamglogene autotemcel wherever you encounter it, plus the key facts at a glance.
- Generic name
- Exagamglogene autotemcel
- Brand name
- Casgevy
- Development code
- CTX001
- Drug class
- Gene editing therapy
- Manufacturer
- Vertex Pharmaceuticals / CRISPR Therapeutics
- How it's taken
- A complex multi-step process: stem cell collection via apheresis, gene editing at a manufacturing facility (takes several months), chemotherapy conditioning, then a single IV infusion of the edited cells.
The first CRISPR-based gene editing therapy to receive regulatory approval, authorized first in the UK in November 2023 and then by the FDA in December 2023. A patient's own stem cells are edited to produce high levels of fetal hemoglobin, which prevents red blood cells from sickling.
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Where Exagamglogene autotemcel fits
First CRISPR-based gene-editing therapy approved for transfusion-dependent beta-thalassemia. A potentially curative one-time treatment, positioned as an alternative to lifelong transfusions for eligible patients.
How Exagamglogene autotemcel works
Doctors collect a patient's own blood stem cells, then use CRISPR gene editing to disable a gene called BCL11A that normally switches off fetal hemoglobin production after birth. The edited cells are infused back into the patient after chemotherapy clears space in the bone marrow. The modified stem cells then produce red blood cells rich in fetal hemoglobin, which prevents sickling.
Mechanism: CRISPR/Cas9 gene-edited autologous stem cell therapy that boosts fetal hemoglobin production
Side effects and safety
Side effects are mainly related to the chemotherapy conditioning (busulfan) needed before the cell infusion, including low blood counts, mouth sores, nausea, and infection risk. Infertility from chemotherapy is a significant concern. The label also warns that the edited cells might not take hold (engraftment failure), in which case backup stem cells are given. Platelet recovery can be delayed, which raises the risk of bleeding, so frequent blood counts are needed. Serious allergic reactions, including anaphylaxis, can happen during or after the infusion, and unintended off-target gene edits cannot be ruled out. A negative pregnancy test is required before stem cell collection and again before chemotherapy, and birth control is needed through at least 6 months after the infusion. Long-term gene editing safety monitoring is ongoing.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Exagamglogene autotemcel
A complex multi-step process: stem cell collection via apheresis, gene editing at a manufacturing facility (takes several months), chemotherapy conditioning, then a single IV infusion of the edited cells. Requires hospitalization at a specialized center.
Availability and cost
Only available as the brand-name product.
One-time CRISPR/Cas9 gene-editing therapy requiring patient stem cell collection, ex vivo editing, myeloablative conditioning, and transplantation. The complex manufacturing process and curative intent explain the one-time cost.
Help paying for Casgevy
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Insurance and case manager help
A Care Manager answers questions, shares guides, and works with your treatment center on the logistics of your gene therapy.
The official page does not say who qualifies. Ask the program. · source - Travel help
Care Managers check whether you qualify for treatment-related travel and lodging assistance. Eligibility requirements apply.
The official page does not say who qualifies. Ask the program. · source - Other support
Fertility support may be available for sickle cell patients insured by Medicaid in certain states, through the CMS Cell and Gene Therapy Access Model.
For: Medicaid · source
Good to know: Enrollment is not required to receive CASGEVY. The official pages do not describe copay help or who qualifies for travel support. Call 1-833-VERTEX-5, Monday to Friday, 8 am to 8 pm ET.
- From a charity · The Assistance FundSickle Cell Disease fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…” - From a charity · Cooley's Anemia FoundationSupport for Significant Travel to Treatment Centers fundApply directly
Pays for: Travel to a major thalassemia treatment center for comprehensive care, up to $500 per year.
The foundation says: “Status not shown on page”
Clinical trial results
In the pivotal trial, 29 of 31 evaluable SCD patients (93.5%) had no severe vaso-occlusive crises for at least 12 months in a row. All treated patients engrafted and none needed backup cells. Also approved for transfusion-dependent beta-thalassemia (January 2024), where 32 of 35 patients (91.4%) stopped needing transfusions for at least 12 months. On July 1, 2026, FDA expanded approval to patients aged 2 and older for both conditions (originally 12 and older).
Development history
Casgevy made history as the first CRISPR-based medicine to receive regulatory approval anywhere, first in the UK (November 2023) then FDA approval on December 8, 2023 for people 12 and older. On July 1, 2026, the FDA expanded its approval to patients aged 2 and older with sickle cell disease or transfusion-dependent beta-thalassemia. It represents a potential functional cure for sickle cell disease.
Explore Sickle Cell Disease and Thalassemia trials
Other Sickle Cell Disease & Thalassemia treatments
Exagamglogene autotemcel in Trial Friend News and Guides
Common questions about Exagamglogene autotemcel
▸What is Exagamglogene autotemcel (Casgevy)?
The first CRISPR-based gene editing therapy to receive regulatory approval, authorized first in the UK in November 2023 and then by the FDA in December 2023. A patient's own stem cells are edited to produce high levels of fetal hemoglobin, which prevents red blood cells from sickling.
▸How does Exagamglogene autotemcel work?
Doctors collect a patient's own blood stem cells, then use CRISPR gene editing to disable a gene called BCL11A that normally switches off fetal hemoglobin production after birth. The edited cells are infused back into the patient after chemotherapy clears space in the bone marrow. The modified stem cells then produce red blood cells rich in fetal hemoglobin, which prevents sickling.
▸What are the side effects of Exagamglogene autotemcel?
Side effects are mainly related to the chemotherapy conditioning (busulfan) needed before the cell infusion, including low blood counts, mouth sores, nausea, and infection risk. Infertility from chemotherapy is a significant concern. The label also warns that the edited cells might not take hold (engraftment failure), in which case backup stem cells are given. Platelet recovery can be delayed, which raises the risk of bleeding, so frequent blood counts are needed. Serious allergic reactions, including anaphylaxis, can happen during or after the infusion, and unintended off-target gene edits cannot be ruled out. A negative pregnancy test is required before stem cell collection and again before chemotherapy, and birth control is needed through at least 6 months after the infusion. Long-term gene editing safety monitoring is ongoing.
▸How is Exagamglogene autotemcel taken?
A complex multi-step process: stem cell collection via apheresis, gene editing at a manufacturing facility (takes several months), chemotherapy conditioning, then a single IV infusion of the edited cells. Requires hospitalization at a specialized center.
▸Is Exagamglogene autotemcel FDA approved?
Yes, Exagamglogene autotemcel (Casgevy) is FDA approved (2023) for the treatment of Sickle Cell Disease and Thalassemia.
▸What made Casgevy historically significant?
Casgevy made history as the first CRISPR-based medicine to receive regulatory approval anywhere in the world, first in the UK in November 2023 and then by the FDA on December 8, 2023. It demonstrated that gene editing could be used as a practical medical treatment.
▸How does Casgevy compare to Lyfgenia for sickle cell disease?
Both were approved on the same day (December 8, 2023) but use different approaches. Casgevy uses CRISPR gene editing to boost fetal hemoglobin, while Lyfgenia uses a lentiviral vector to add a modified beta-globin gene. Lyfgenia carries a black box warning for blood cancer risk that Casgevy does not have.
▸What is the treatment process for Casgevy?
The process involves stem cell collection via apheresis, gene editing at a manufacturing facility (taking several months), chemotherapy conditioning with busulfan to clear bone marrow space, then a single IV infusion of edited cells. It requires hospitalization at a specialized center.
▸Does Casgevy affect fertility?
The busulfan chemotherapy conditioning required before Casgevy infusion carries a significant risk of infertility. Patients should discuss fertility preservation options (such as egg or sperm banking) with their medical team before beginning the treatment process.
▸How effective is Casgevy for sickle cell disease?
In the pivotal trial, 29 of 31 evaluable SCD patients aged 12 and older (93.5%) had no severe vaso-occlusive crises for at least 12 months in a row. In a trial of children aged 5 to 11, all 8 evaluable patients reached that goal. All treated patients engrafted and none needed their backup cells.
▸Is Casgevy also approved for thalassemia?
Yes. Casgevy received FDA approval for transfusion-dependent beta-thalassemia in January 2024, expanding beyond its initial sickle cell disease indication. The same CRISPR mechanism that boosts fetal hemoglobin addresses the underlying anemia in both conditions.
▸What long-term safety monitoring is needed after Casgevy?
Long-term gene editing safety monitoring is ongoing, including surveillance for any unintended genetic changes (off-target effects). Patients are enrolled in long-term follow-up studies to track both the durability of benefit and any delayed safety concerns.