CAR T-cell therapy

Overview

CAR T-cell therapy is a form of cell therapy that empowers the body’s own immune system to fight cancer. This innovative approach involves extracting a patient's T-cells, a type of white blood cells essential for immune defense, and modifying them to recognise and destroy the cancer cells. The reprogramming is done in a laboratory, where the T-cells are genetically modified to express synthetic receptors known as chimeric antigen receptors (CARs).

These CARs are engineered molecules that enable the modified T-cells to identify and latch onto specific proteins present on cancer cells, which the natural immune system might otherwise overlook.

How CAR T-Cell Therapy Works?

Here's how CAR T-cell therapy works:

• T-Cell Collection: The patient’s T-cells are collected from their bloodstream using a process called leukapheresis.
• Genetic Engineering: In the lab, these T-cells are modified using a viral vector to insert genes that encode CARs, receptors specifically designed to target antigens on cancer cells.
• Cell Expansion: The altered T-cells are then grown in large numbers under controlled conditions.
• Reinfusion: Once enough cells are produced, they are infused back into the patient.
• Cancer Cell Targeting: These CAR-equipped T-cells now circulate in the body, seeking out and attacking cells that express the targeted antigen.
• Persistence and Immune Memory: Some modified T-cells remain in the body, continuing to multiply and providing long-term immune surveillance that can help prevent recurrence.

This therapy has achieved significant success in treating certain blood cancers like leukemia and lymphoma. However, due to its complexity and intensity, it comes with potential risks, including cytokine release syndrome (CRS) and neurological side effects, which may require close monitoring and management.

Who Is Eligible for CAR T-Cell Therapy?

Ideal candidates usually meet the following criteria:

• Diagnosis of Blood Cancer: Commonly used for cancers such as acute lymphoblastic leukemia (ALL) or diffuse large B-cell lymphoma (DLBCL).
• Presence of Target Antigens: The cancer cells must express the specific antigen that the CAR T-cells are designed to recognize.
• Resistance to Prior Treatment: Often considered when traditional therapies (e.g., chemotherapy, radiation) have failed or the disease has relapsed.

Who May Not Be Suitable for CAR T-Cell Therapy?

Contraindications include:

• Severe Organ Impairment: Those with significant damage to organs like the heart, liver, or kidneys may be at higher risk.
• Active Infections: Infections at the time of treatment can increase the risk of complications.
• Neurological Disorders: Pre-existing brain or nerve-related conditions might increase treatment-related toxicity.

Preparing for the Procedure

• Comprehensive Evaluation: A detailed assessment of the patient's health status, disease characteristics, and previous treatments.
• T-Cell Collection: Performed through leukapheresis.
• Cell Engineering: Genetic modification in a laboratory setting to add the CAR.
• Cell Multiplication: Cultured until enough modified cells are available for therapy.

Treatment Process

• Lymphodepleting Chemotherapy: Administered before reinfusion to reduce existing immune cells, making room for the CAR T-cells to function effectively.
• Infusion of CAR T-Cells: The engineered cells are returned to the patient via IV.
• Post-Infusion Monitoring: Patients are closely observed for side effects, particularly for immune-related reactions like CRS or neurological symptoms.

Post-Treatment Care

• Managing Adverse Effects: Prompt treatment of symptoms such as high fever, confusion, or low blood pressure.
• Infection Prevention: Since immunity may be temporarily reduced, infection control measures are crucial.
• Supportive Medications: Drugs may be administered to prevent or reduce the severity of side effects like CRS.

Benefits of CAR T-Cell Therapy

• High Success Rates in Blood Cancers: Remarkable outcomes have been observed, especially in patients unresponsive to conventional therapies.
• Precision Medicine: Targets cancer cells with minimal damage to surrounding healthy tissues.
• Potential for Long-Term Remission: Some patients experience durable, cancer-free periods after treatment.
• Expanding Potential: Research is actively exploring CAR T-cell use in solid tumors and other cancer types.
• Improved Survival: Studies have shown increased survival rates in many patients, marking a major advancement in oncology.

Possible Side Effects of CAR T-Cell Therapy

While CAR T-cell therapy has shown significant success in treating certain cancers, it may also lead to side effects, some of which can be serious. The two most commonly observed complications are cytokine release syndrome (CRS) and neurological effects.

Cytokine Release Syndrome (CRS)

CRS is a systemic inflammatory response caused by the rapid activation of immune cells and release of cytokines after CAR T-cell infusion. It can range from mild to severe and typically occurs within a few days of treatment.

Common symptoms include:

• Difficulty breathing (dyspnea)
• High fever
• Low blood pressure (hypotension)
• Rarely, complications affecting the heart or lungs

Neurological Side Effects

CAR T-cell therapy may also affect the nervous system. These side effects often develop shortly after treatment and may resolve over time, but some can be more serious.

Neurologic symptoms may include:

• Trouble speaking (aphasia)
• Loss of balance or coordination
• Mental confusion or disorientation
• Difficulty with writing (dysgraphia)
• Headaches
• Seizures
• Muscle tremors or involuntary twitching

Other Potential Side Effects

Aside from CRS and neurologic symptoms, patients may experience additional side effects, such as:

• Allergic reactions during or shortly after infusion
• Fatigue or extreme tiredness
• Easy bruising or bleeding due to low platelet counts
• Electrolyte imbalances, such as:
  • Low potassium levels (hypokalemia)
  • Low sodium levels (hyponatremia)
• Heightened risk of infections, as the immune system may become temporarily weakened after treatment

Most side effects can be managed with prompt medical attention. Patients undergoing CAR T-cell therapy are closely monitored during and after treatment to detect and address any adverse reactions early.

CAR T-cell Therapy in India

CAR T-cell Therapy is available in hospitals in India at nearly 1/20th the cost compared to Western countries. The overall expense can vary based on several factors such as the hospital's infrastructure, location, room category, and any additional care required in case of complications.

Yatharth Hospital, Noida Extension, India, offers state-of-the-art facilities and experienced oncologists and Bone Marrow Transplant specialists, providing CAR T-cell Therapy for cancer patients. At Yatharth Hospitals, we have a team of highly skilled and experienced oncologists and hematologists for performing CAR T-cell therapy. The hospital also employs a multidisciplinary approach, utilizing advanced diagnostic tools and monitoring techniques to enhance treatment precision and ensure patient safety. For personalised care plans and detailed cost estimates, we recommend reaching out to Yatharth Hospitals directly.