Cell and Gene Therapy Treatments

Gene therapy is an innovative approach to treating genetic diseases. Doctors can target the underlying cause rather than just treating the symptoms. Our genes act like instructions for how our body’s cells should work. If a gene is faulty or missing, it can cause health issues, such as cancer, blood disorders like hemophilia and sickle cell disease, neuromuscular diseases, and blindness. Gene therapy aims to correct these faulty genes.

A similarly innovative approach is cell therapy which involves transferring cells into the patient’s body to repair or replace damaged cells, or enhance the immune system’s ability to fight the disease. These cells, either from the patient (autologous) or a donor (allogeneic), are processed in a lab and then introduced into the body to help treat conditions like cancer or blood disorders.

For patients who are eligible for cell and gene therapy at CHLA, it offers life-changing potential where other treatments may not have worked. With many gene therapy clinical trials in development, gene therapy is on track to becoming one of the most important new medical treatments.

We offer a range of FDA-approved cell and gene therapies designed to treat various disorders:

  • Casgevy® (treats sickle cell disease and transfusion-dependent beta thalassemia)
  • Elevidys® (treats Duchenne muscular dystrophy)
  • Hemgenix® (treats hemophilia B)
  • Kymriah® (treats B-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma)
  • Luxturna® (treats inherited retinal disease)
  • Lyfgenia™ (treats sickle cell disease)
  • Omisirge® (treats patients with leukemia who need a bone marrow transplant)
  • Roctavian™ (treats hemophilia A)
  • Zolgensma® (treats spinal muscular atrophy)
  • Zynteglo™ (treats transfusion-dependent beta thalassemia)

How Does Gene Therapy Work?

Genetic disorders are caused by abnormalities in a person’s genes. Gene therapy focuses on pinpointing these faulty pieces of genetic code to stop or slow the disease. Treatments directly target the root cause, modify specific genes to transform them and improve the body’s ability to fight the disease.

There are three main approaches:

  • Gene Replacement: This method involves replacing a disease-causing gene with a healthy copy.
  • Gene Silencing: Inactivating or “turning off” a harmful disease-causing gene that is not functioning properly.
  • Gene Editing: Adding, removing or altering specific parts of the gene and introducing it to the body.

Viral vectors, which are modified and harmless viruses, can be used to deliver these therapies directly into a cell. Some approaches do not require carriers.

While gene therapy focuses on modifying genetic code to correct or enhance gene function, cell therapy involves transferring healthy or modified cells into the patient’s body to repair tissues or improve immune responses. Cells can be collected from the patient’s own body (autologous) or from a matched donor patient (allogeneic).

Doctors may recommend one type of therapy over the other depending on the condition being treated.

Types of Gene Therapy Approaches

At CHLA, we use two types of procedures to administer current gene therapies: gene-modified cell therapy (ex-vivo gene therapy) and in-vivo.

What Is Gene-Modified Cell Therapy (or Ex-Vivo Gene Therapy)?

This method is a combination of gene and cell therapy, where gene correction is done outside of the body and is the most common. A process called apheresis, which uses a special machine, is used to collect the patient’s blood. The blood is then taken to the lab where the blood stem cells are separated out, and viral vectors—modified and harmless viruses—are used to transfer the corrected gene into the patient’s cultured cells, which are cells grown outside the body in a controlled environment. These modified cells are then reintroduced into the body through intravenous (IV) infusion, where they can replicate and help treat the disease.

An example of gene-modified cell therapy is CAR T-cell therapy, where a patient’s immune cells (T-cells) are collected, genetically modified in a lab, and then infused back into the body. The altered cells will then recognize and attack the diseased cells. This treatment has been highly effective for certain blood cancers, such as acute lymphoblastic leukemia. Gene-modified cell therapy demonstrates a fusion of gene therapy and cell therapy to achieve transformative outcomes.

What is In-Vivo Gene Therapy?

With the in-vivo method, the therapy is infused directly into the human body, most commonly by an IV through a vein. A viral vector—a modified virus used to deliver genetic material into cells—carries a therapeutic protein to directly modify the patient’s genes inside the body. This method offers a unique advantage for treating conditions that are resistant to traditional therapies.

What are the Benefits and Risks of Gene Therapy?

Gene therapy offers exciting possibilities for treating genetic disorders and can improve the overall quality of life for our patients and families. Like any advanced medical treatment, it comes with both benefits and risks.

Benefits of Gene Therapy

Gene therapy offers hope to children dealing with diseases that have few or no effective treatment options, particularly rare genetic disorders and certain cancers that resist traditional therapies. This innovative medicine is expanding to target a wide range of conditions and has been FDA-approved to treat several inherited diseases, such as hemophilia, sickle cell disease, and muscular dystrophy.

Unlike treatments that focus on symptoms, gene therapy addresses the underlying cause, potentially offering a more lasting solution. Early genetic screening, especially in newborns, can allow us to treat a child before they’ve even had symptoms. For conditions like sickle cell disease or hemophilia, gene therapy offers a chance to reduce or even eliminate the need for lifelong treatments. Many gene therapies require only one-time or limited treatments, providing long-term benefits without the need for ongoing therapy.

With more than 1,000 gene therapies currently in clinical development, gene therapy is advancing rapidly. This positions gene therapy at the forefront of next-generation medicine, promising to reshape pediatric health care with ongoing innovations.

Risks of Gene Therapy

Though promising, gene therapy comes with potential risks. Depending on the specific gene therapy, these risks may include temporary immune suppression (loss in immune function), harmful immune responses, damage to healthy cells, or even gene toxicity that could increase the risk of cancer.

Continuous monitoring after treatment is important to detect and manage any side effects early. Our dedicated team provides comprehensive, long-term monitoring to support each child’s recovery and well-being, offering families peace of mind. While some respond well to treatment, outcomes can vary. Although these therapies are often a one-time treatment, long-term care and monitoring are required to address any potential complications. The long-term effects of gene therapy are also still unknown, but clinical trials and research are closely monitored by the FDA and the National Institutes of Health (NIH) to help reduce risks and improve outcomes for future patients.

Despite the challenges and potential risks, gene therapy represents a groundbreaking advancement in pediatric care and offers the potential for a brighter future for patients.

Treatments Offered at CHLA

Casgevy (Gene Therapy) for Sickle Cell Disease and Transfusion-Dependent Beta Thalassemia

CHLA is one of a few pediatric hospitals on the West Coast to offer Casgevy, which is a one-time gene therapy that can be used to treat two conditions. Designed for people ages 12 and older who have sickle cell disease (SCD) with frequent pain crises or those with transfusion-dependent beta thalassemia. It is the first cell-based gene therapy treatment using CRISPR-Cas9 gene editing technology, which modifies an organism's DNA, to be approved by the FDA. Both conditions affect red blood cells due to errors in the production of hemoglobin. Casgevy uses the patient's own blood stem cells to boost the production of a special type of hemoglobin called hemoglobin F, which can improve the production and function of red blood cells. Once the cells have been treated, they are infused into the body using an IV. This treatment can help reduce and even eliminate pain crises in children with sickle cell disease and the need for regular blood transfusions in children with beta thalassemia. Stem cell collection can take place in our Infusion Center, followed by treatment which is done in our inpatient bone marrow transplant (BMT) unit. Patients remain in the hospital for four to six weeks post-treatment for careful monitoring by our specialized team.

Elevidys (Gene Therapy) for Duchenne Muscular Dystrophy

CHLA is one of the few centers on the West Coast to offer Elevidys, a gene therapy designed to treat Duchenne Muscular Dystrophy (DMD) in boys ages 4 and older. As one of the nation’s highest-volume centers for treating children with Elevidys gene therapy, CHLA has cared for a leading number of patients with DMD. DMD is caused by a defect in the dystrophin gene that results in abnormalities or a lack of dystrophin protein, which helps support muscle cells. Children with DMD experience muscle weakness at a young age, but Elevidys helps the body produce a protein that includes essential parts of dystrophin, which can slow the progression of muscle degeneration. Treatment consists of a single-dose infusion, primarily done in our outpatient Infusion Center with essential pre- and post-infusion steps, including ongoing monitoring.

Hemgenix (Gene Therapy) for Hemophilia B

CHLA played a critical role in Hemgenix clinical trials that paved the way for its FDA approval in 2022 and we are one of a few centers on the West Coast to offer this treatment. Available for males 18 and older, it is the first and one of only two gene therapy treatments for hemophilia B, a rare genetic bleeding disorder. Patients with hemophilia B do not have enough of a blood protein called Factor IX, which is needed for blood clotting. As a result, they can experience prolonged bleeding. Hemgenix addresses this by delivering a functional copy of the F9 gene directly to liver cells, where they then produce the missing Factor IX and can help prevent and control bleeding. The treatment is done in our outpatient Infusion Center as a single IV infusion, typically completed within one to two hours, offering a potentially life-changing option for managing hemophilia B.

Kymriah (CAR T-Cell Therapy) for B-cell Acute Lymphoblastic Leukemia (ALL) and Diffuse Large B-Cell Lymphoma (DLBCL)

CHLA specialists played a key role in the clinical trials that led to the approval of Kymriah, a gene therapy for B-cell acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL).

Kymriah is specifically designed for children and young adults up to 25-years old with relapsed or treatment-resistant B-cell ALL and DLBCL. B-cell ALL is an aggressive blood cancer characterized by an overproduction of immature white blood cells in the blood and bone marrow. DLBCL is an aggressive type of non-Hodgkin lymphoma affecting the lymphatic system. Kymriah reprograms the patient’s T-cells (a type of white blood cell crucial to the immune system) to recognize and destroy cancerous B-cells in the body. The process involves collecting cells from the patient, modifying them in a lab, and reintroducing them to target and destroy cancer cells, including any remaining cells post-treatment. After treatment, patients receive ongoing support and monitoring to ensure the best possible outcomes.

Luxturna (Gene Therapy) for Vision Loss from Inherited Retinal Dystrophy

Luxturna is a gene therapy designed for patients 12 months or older with inherited retinal disease (congenital blindness). To be eligible, patients must have enough remaining retinal cells, the thin tissue at the back of the eye responsible for vision. The CHLA Vision Center performed the first Luxturna treatment on the West Coast in 2018 and in 2024 completed its 100th retinal gene therapy procedure. CHLA has treated more patients with this gene therapy than any other center in the nation.

Inherited retinal disease is caused by mutations in the RPE65 gene, which is essential for producing the protein necessary for vision. Luxturna works by delivering a functional copy of the RPE65 gene directly into the retinal cells using a specially designed viral vector (a harmless virus used to carry a therapeutic gene into a cell). This helps the retina convert light into electrical signals, allowing the cells to produce the needed protein for vision. Many patients experience significant improvements in functional vision following this therapy. Luxturna is given as a surgical injection beneath the retina of each eye, performed in the operating room (OR). After one eye is treated, the second eye will be treated at least six days later.

Lyfgenia (Gene Therapy) for Sickle Cell Disease

CHLA offers Lyfgenia, an FDA-approved gene therapy for patients ages 12 and older with sickle cell disease (SCD). Children with this condition have abnormal hemoglobin in their red blood cells, which can cause these cells to be crescent-shaped, or sickle-shaped. The sickle-shaped red blood cells can cause blood flow to be blocked, leading to health problems and pain. Lyfgenia uses the patient’s own blood stem cells (from which red blood cells are produced) to add a healthy copy of the globin gene to those cells. Once treated, the cells are then infused into the body through an IV where they begin to make healthy blood cells, helping to decrease or stop symptoms of sickle cell disease. Stem cell collection typically takes place in our outpatient Infusion Center, followed by treatment which is done in our inpatient bone marrow transplant (BMT) unit. Patients remain in the hospital for three to six weeks post-treatment for careful monitoring by our specialized care team.

Omisirge (Cell Therapy) for Patients Who Have Leukemia

Omisirge is an FDA-approved cell therapy derived from umbilical cord blood, designed to enhance outcomes in stem cell transplantation for patients ages 12 and older who have leukemia. It involves using live cells to replace or repair damaged tissues or to improve the immune system’s ability to fight diseases. During its development, nicotinamide (a form of vitamin B3) is used in the cell expansion process to increase the number and function of stem cells. These enhanced cells attach to the body faster and more reliably than traditional cord blood transplants.

This quicker attachment significantly reduces the period when white blood cell counts are dangerously low, lowering the risk of infections and other complications. CHLA is proud to offer this groundbreaking cell therapy, positioning ourselves as one of the few pediatric centers on the West Coast to administer Omisirge.

Roctavian (Gene Therapy) for Hemophilia A

CHLA is one of the few centers on the West Coast to offer Roctavian, a gene therapy designed specifically for males aged 18 and older with hemophilia A. This hereditary disorder is caused by a lack of Factor VIII protein, which is needed for blood clotting. People with hemophilia A are at higher risk of prolonged bleeding. Roctavian addresses this symptom by delivering a functional copy of the Factor VIII gene directly to the liver cells, enabling the body to produce the necessary protein for clotting. By targeting the underlying genetic cause of hemophilia A, this therapy provides a long-term solution, unlike traditional treatments that require regular infusions. Treatment is done in our outpatient Infusion Center as a single IV infusion, typically completed within two to five hours.

Zolgensma (Gene Therapy) for Spinal Muscular Atrophy (Type 1)

CHLA is one of the few centers on the West Coast offering Zolgensma, an advanced gene therapy option for spinal muscular atrophy (SMA). Since treating our first patient with SMA in 2020, our expert team has provided comprehensive care for children diagnosed with this serious condition. Zolgensma is a one-time treatment designed for children under two with SMA, a genetic condition that causes muscle weakness and atrophy–where the muscles waste away–affecting essential functions like breathing, swallowing, and movement. This treatment works by delivering a healthy copy of the SMN1 gene, which produces the "survival of motor neuron" (SMN) proteins needed for muscle control. By restoring the function of these proteins, Zolgensma helps slow the progression of the disease. Treatment is typically done in our outpatient Infusion Center with a single IV infusion, offering a potentially life-saving option for young children with SMA.

Zynteglo (Gene Therapy) for Transfusion-Dependent Beta Thalassemia or Cooley's Anemia

Zynteglo is a gene therapy designed for children aged four and older with transfusion-dependent beta thalassemia, also known as Cooley's Anemia. CHLA is one of the few centers on the West Coast to offer this treatment. This inherited condition prevents the body from producing the beta protein needed for proper hemoglobin function in red blood cells. As a result, it causes severe anemia that requires regular blood transfusions and monitoring to manage the condition.

Zynteglo works by using the patient’s own blood stem cells, which are then sent to the lab to be modified, where functional copies of the beta-globin gene are added to the collected cells. The corrected cells are then reintroduced into the body through an IV infusion, enabling the production of healthy hemoglobin and allowing the body to create normal red blood cells. Stem cell collection typically takes place in our Infusion Center, followed by treatment which is done in our inpatient bone marrow transplant (BMT) unit, with close monitoring by our expert team. Clinical trials have shown promising outcomes, with many patients no longer needing transfusions after receiving Zynteglo.

Cell and Gene Therapy at Children’s Hospital Los Angeles

At CHLA, each child receives advanced and personalized care in our state-of-the-art facilities from our team of renowned experts who are committed to transforming lives. From the first consultation to long-term follow-up, our dedicated team of specialists is with you every step of the way, providing compassionate, expert care.

Discover how cell and gene therapy at CHLA can transform your child’s future.

Contact Us

Our specialists at CHLA are here to support you. To see if your child might qualify for cell and gene therapy, please contact the appropriate team based on your child’s condition:

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