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Casgevy is a gene therapy that is used to treat certain inherited blood conditions. It changes your stem cells to provide a gene that helps certain people with either sickle cell disease or beta thalassemia. In order to receive Casgevy, you will need multiple procedures and treatments, including a bone marrow transplant. Altogether, this treatment may take more than six months to complete. Each of these procedures and treatments carries its own risks and side effects. Make sure that you talk with your health care provider to understand the entire process.

Uses

What is Casgevy used for?

Casgevy (exagamglogene autotemcel) is used to treat certain people with either sickle cell disease (SCD) or beta thalassemia.

Casgevy may also be used for other conditions as determined by your health care provider.

How does Casgevy work (mechanism of action)?

People with sickle cell disease and beta thalassemia have changes (mutations) in a gene in their red blood cells. This changes the way their red blood cells form and function, which can cause many serious health problems. 

Casgevy is a type of gene therapy, which means that it changes a gene to provide you with one that helps your red blood cells to make high levels of a substance called fetal hemoglobin. Hemoglobin is the substance in your red blood cells that carries oxygen. Once your treatment with Casgevy is completed, the changed gene is a permanent part of your body. Having more fetal hemoglobin may reduce or stop sickle cell crises in people with sickle cell disease and prevent people with beta thalassemia from needing blood transfusions.

How is Casgevy supplied (dosage forms)?

Brands and other names

  • Casgevy

Dosage forms and strengths

Casgevy is available in an injectable form that is given by a health care provider.

How should I store Casgevy?

Casgevy is given by a health care provider in a hospital or clinic. You will not store it at home.

Side Effects

What are the most common side effects of Casgevy?

The most common side effects of Casgevy are listed below. These side effects may vary, depending on the condition that is being treated. Tell your health care provider if you have any of these side effects that bother you.

  • Mouth or lip sores
  • Fever
  • Decreased appetite
  • Severely low platelet levels (see below)
  • Low neutrophil levels (see below)

There may be other side effects of Casgevy that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of Casgevy?

While less common, the most serious side effects of Casgevy are described below, along with what to do if they happen.

Severe Allergic Reactions. Casgevy may cause allergic reactions, which can be serious. Get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Low Neutrophil Levels. After treatment with Casgevy, you may have a low level of white blood cells for a period of time, including a low number of white blood cells called neutrophils, which is known as neutropenia. White blood cells help prevent infection. Having a low level may increase your risk of infection. Tell your health care provider right away if you have any of the following symptoms of low white blood cell levels.

  • Infection
  • Tiredness
  • Sore throat, cough, or shortness of breath
  • Mouth or throat sores
  • Swollen lymph nodes
  • Fever, chills, severe headache, or sweats

Severely Low Platelet Levels. After treatment with Casgevy, you may have a severely low number of platelets in your blood, also called thrombocytopenia, for a period of time. Platelets help to form blood clots. Having a low level of platelets may increase your risk of bleeding. Tell your health care provider if you have any of the following symptoms of low platelet levels.

  • Bleeding that does not stop
  • Nosebleeds
  • Easy bruising or bleeding
  • Blood in your stool (poop), pee, or vomit
  • Coughing up blood

Warnings & Precautions

Who should not use Casgevy?

Allergies to Ingredients. People who are allergic to any of the following should not use Casgevy.

  • Casgevy
  • Dextran 40
  • Dimethylsulfoxide (DMSO)
  • Exagamglogene autotemcel
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in Casgevy.

What should I know about Casgevy before using it?

Casgevy is a personalized gene therapy that is given by a health care provider in a hospital. Make sure that you discuss the entire treatment plan with your health care provider before it starts.

Before your treatment with Casgevy, your stem cells will be collected from your body and sent to a lab. It may take up to six months for your edited stem cells to be prepared in the lab. Before your stem cells are collected, you may need to stop taking certain medicines. You may also need to receive a blood transfusion. It is important to follow all instructions and keep all appointments with your health care provider during this process.

Before receiving treatment with Casgevy, your health care provider will give you “conditioning” medicine that will clear all of the bone marrow cells from your body. After this is done, you will be at high risk of infection and bleeding and will need to stay in the hospital for the rest of your treatment. While you are there, you may need to take medicines to prevent or treat side effects from the conditioning medicine. 

Once your bone marrow is cleared, your edited stem cells (Casgevy) will be infused into your vein. (This is known as a bone marrow transplant.) These stem cells will then rebuild your bone marrow, a process called engraftment. It can take four to six weeks for this to happen. You may need to remain in the hospital for this entire period. While you are waiting for engraftment, you will have very little or no white blood cells or platelets, which means you will be at high risk of infection and bleeding.

In rare cases, your edited stem cells may not engraft at all. This is called engraftment failure. If this happens, your health care provider will infuse your original stem cells back into your body. This means that your original stem cells will replace your edited stem cells, and you will not get any benefit from Casgevy.

The “conditioning” medicine that is used to clear your bone marrow cells from your body may make it difficult for you to get pregnant or get your partner pregnant. If you may want to have children in the future, speak with your health care provider about your options.

If you are able to get pregnant or get someone else pregnant, you should use an effective form of birth control throughout your entire treatment process with Casgevy. This means that you should start birth control when you are getting ready to have your stem cells collected and continue using birth control for at least six months after receiving Casgevy.

Do not donate any blood, tissues, cells, or organs to another person after you get Casgevy. 

Casgevy is a type of gene therapy. It is designed to only edit one specific gene in your stem cells. But it is possible that Casgevy could accidentally edit another part of your stem cell’s genes. These unexpected edits have not been reported in anyone who has received Casgevy. But your health care provider will monitor you for any possible changes in your genes.

What should I tell my health care provider before using Casgevy?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if Casgevy is right for you.

In particular, make sure that you discuss any of the following.

  • Current infection, infection that keeps coming back, or low levels of white blood cells
  • Bleeding problems or low levels of platelets
  • Hepatitis
  • HIV or AIDS
  • Prior bone marrow transplant (BMT), also called a hematopoietic stem cell transplant (HSCT)

Other Medicines and Supplements. Casgevy may interact with other medicines and supplements. Before receiving Casgevy, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. Do not get Casgevy if you are pregnant or trying to get pregnant. It is not known if or how Casgevy could affect pregnancy or harm an unborn baby. If you are able to get pregnant, your health care provider will confirm that you are not pregnant before you begin treatments related to Casgevy. You should use an effective form of birth control from the time that your stem cells are collected until six months after you have received your treatment with Casgevy. 

Breastfeeding. It is not known if Casgevy passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should get Casgevy while breastfeeding or breastfeed after getting this medicine.

How can I get more information about Casgevy?

For more information about Casgevy, you can visit the drugmaker’s website at www.casgevy.com or call 833-837-8395.

Interactions

Does Casgevy interact with foods or drinks?

There are no known interactions between Casgevy and foods or drinks.

It is unknown if drinking alcohol will affect Casgevy, but drinking can slow your immune response and make it harder for your body to fight infection. Follow your health care provider’s guidance about limiting or avoiding alcohol while you are receiving treatments related to Casgevy. 

Does Casgevy interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before beginning treatments related to Casgevy.

  • Deferiprone (Ferriprox), deferoxamine (Desferal), or deferasirox (Exjade, Jadenu), which is a medicine used to lower the amount of iron in your body
  • Crizanlizumab (Adakveo), which is a medicine used to treat sickle cell disease
  • Hydroxyurea (Hydrea, Siklos, Xromi), which is a medicine used to treat sickle cell disease and some cancers
  • Voxelotor (Oxbryta), which is a medicine used to treat sickle cell disease
  • Filgrastim (Neupogen) or sargramostim (Leukine), which is a medicine that can be used to help your bone marrow make more cells

This may not be a complete list of medicines that can interact with Casgevy. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much Casgevy?

If you or someone else has used too much Casgevy, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of Casgevy?

You get Casgevy and its related treatments from a health care provider at a health care facility. Keep all appointments to help your treatment work. If you need to miss an appointment, contact your health care provider right away.