CAR T-Cell Therapy: What It Is & How It Works

What is CAR T Cell Therapy?

CAR T-cell therapy revolutionises cancer treatment by harnessing the body’s immunity to fight the disease. This innovative immunotherapy modifies a patient’s T-cells to recognise and attack cancer cells more effectively. The process involves extracting T-cells from the patient’s blood, genetically engineering them to produce Chimeric Antigen Receptors (CARs), and reinfusing them into the patient’s body.

This targeted approach offers significant advantages over traditional cancer treatments like chemotherapy and radiation, as it precisely eliminates cancer cells while sparing healthy ones, potentially reducing severe side effects.

What Conditions can CAR T-cell Therapy Treat?

CAR T-cell therapy primarily treats certain blood cancers, including:

• Acute Lymphoblastic Leukaemia (ALL): Shows remarkable success in treating relapsed or refractory ALL in children and adults.
• Diffuse Large B-cell lymphoma (DLBCL): Approved for treating relapsed or refractory DLBCL.
• Follicular Lymphoma: Currently under investigation as a potential treatment option.
• Multiple Myeloma: Researchers are studying its effectiveness for this condition.

While CAR T-cell therapy has mainly focused on blood cancers, scientists actively explore its potential in treating solid tumours like breast, lung, and brain cancers.

How does CAR T-cell Therapy Work?

The CAR T-cell therapy process involves several steps:

• T-cell Collection: Doctors collect the patient’s T-cells through leukapheresis, separating them from other blood components.
• Genetic Engineering: Laboratory technicians modify the collected T-cells to express CARs on their surface, designed to recognise specific cancer cell antigens.
• T-cell Expansion: The genetically engineered CAR T-cells multiply in the laboratory to create many specialised cells.
• Conditioning Chemotherapy: Patients may undergo chemotherapy to deplete existing T-cells and create space for the new CAR T-cells.
• CAR T-cell Infusion: Doctors infuse the expanded CAR T-cells into the patient’s body through an IV line.
• Monitoring and Follow-up: The medical team monitors the patient for potential CAR T-cell therapy side effects and treatment effectiveness, conducting regular follow-up appointments and tests.

What Happens Before I Have CAR T-cell Therapy?

Before undergoing CAR T-cell therapy, patients go through several preparatory steps:

• Initial Evaluation: The medical team conducts a comprehensive evaluation to determine the patient’s suitability for the therapy.
• Apheresis: Doctors collect T-cells from the patient’s blood through leukapheresis.
• Conditioning Chemotherapy: Some patients receive chemotherapy to prepare their body for the CAR T-cell infusion.
• Supportive Care: The healthcare team provides measures to manage potential side effects & ensure overall well-being during treatment.

What Happens During CAR T-cell Therapy?

During the CAR T-cell therapy procedure:

• T-cell Engineering: Laboratory specialists genetically modify the collected T-cells to express CARs.
• T-cell Expansion: The modified T-cells multiply in the laboratory to ensure a sufficient number for infusion.
• CAR T-cell Infusion: Doctors infuse the expanded CAR T-cells into the patient’s body through an IV line.
• Monitoring and Support: The healthcare team monitors the patient for potential side effects and provides necessary supportive care.

What Happens After CAR T-cell Therapy?

After receiving CAR T-cell therapy:

• Recovery Period: Patients may experience fatigue, fever, and flu-like symptoms as their body responds to the treatment.
• Follow-up Appointments: Regular check-ups help monitor progress and response to therapy.
• Ongoing Monitoring: The medical team continues to watch for signs of disease recurrence or long-term side effects.
• Supportive Care: Patients may receive additional care measures for recovery and overall well-being.
• Long-term Follow-up: Regular appointments monitor for potential long-term effects and ensure continued treatment effectiveness.

Side Effects of CAR T-cell Therapy

While CAR T-cell therapy shows remarkable success, it can lead to potentially severe side effects:

• Cytokine Release Syndrome (CRS): A potentially life-threatening condition causing high fever, chills, low blood pressure, and respiratory distress.
• Neurological Toxicities: Some patients may experience confusion, delirium, seizures, or speech and language impairments.
• Infections: The treatment can weaken the immune system, increasing infection susceptibility.
• Anaemia and Neutropenia: The therapy may decrease red blood cells and specific white blood cells, increasing infection risk.
• Tumour Lysis Syndrome: Rapid cancer cell death can lead to kidney failure and other metabolic disturbances.
• Graft-versus-host Disease (GvHD): In some cases, CAR T-cells may attack healthy cells, leading to GvHD.

The medical team closely monitors and manages these side effects, varying in severity and duration among patients.

What are The Benefits of CAR T-cell Therapy?

Despite potential side effects, CAR T-cell therapy offers significant benefits:

• Targeted Treatment: It specifically targets cancer cells while sparing healthy ones, reducing the risk of severe side effects associated with traditional therapies.
• Personalised Approach: The therapy uses the patient’s own genetically modified T-cells to attack their specific cancer cells.
• Potential for Durable Remission: Some patients experience long-lasting remissions, even with advanced or relapsed cancers that haven’t responded to other treatments.
• Improved Quality of Life: By targeting cancer cells more effectively, CAR T-cell therapy may reduce the disease burden and ongoing treatment needs.
• Ongoing Research: Scientists continuously work to improve the safety and efficacy of CAR T-cell therapy and explore its potential in treating a more comprehensive range of cancers.

How Successful is This Treatment?

The success rate of CAR T-cell therapy varies depending on the cancer type, specific CAR T-cell product, and individual patient characteristics. Clinical trials and real-world experience have shown promising results:

• Acute Lymphoblastic Leukaemia (ALL): Up to 90% of patients achieve remission after treatment in clinical trials for relapsed or refractory ALL.
• Diffuse Large B-Cell Lymphoma (DLBCL): Response rates range from 40% to 60% for patients with relapsed or refractory DLBCL, with some achieving long-lasting remissions.
• Multiple Myeloma: Though research is ongoing, early clinical trials show response rates ranging from 30% to 70%.

Various factors influence success rates, including cancer type, overall health, and previous treatments. The healthcare team evaluates each case individually to provide guidance on potential outcomes.

When to See a Doctor

Consider consulting a doctor about CAR T-cell therapy in the following situations:

• Relapsed or Refractory Cancer: If your cancer has returned after initial treatment or doesn’t respond to standard therapies.
• Aggressive or Advanced Cancer: CAR T-cell therapy may offer a potentially curative option for certain types of aggressive or advanced cancers.
• Lack of Response to Standard Treatments: If you haven’t responded well to traditional cancer treatments.
• Participation in Clinical Trials: If you’re interested in joining clinical trials investigating CAR T-cell therapy for your specific cancer type.
• Second Opinion: Seeking a second opinion from a specialist or comprehensive cancer centre with CAR T-cell therapy expertise can be beneficial.

Always thoroughly discuss with your healthcare team to determine if CAR T-cell therapy suits your specific situation.

Conclusion

CAR T-cell therapy represents a big breakthrough in cancer management, offering new hope to patients who have exhausted traditional options. This innovative approach harnesses the body’s immune system to precisely target and eliminate cancer cells, potentially leading to durable remissions and improved quality of life.

While many people consider it as cancer-free CAR T-cell therapy, particularly in treating certain blood cancers, it’s crucial to be aware of adverse effects and risks. Close monitoring and supportive care from a specialised healthcare team are essential throughout the treatment process.

Ongoing research continues to expand CAR T-cell therapy applications, with clinical trials exploring its potential in treating solid tumours and other cancer types. This personalised and targeted approach represents a promising frontier in the fight against cancer, offering new hope and possibilities for patients and their families.

If you or a loved one has received a cancer diagnosis and wants to explore CAR T-cell therapy, we encourage you to schedule a consultation with our expert team at BMT Hospital in Bangalore. 

FAQs

What does CAR T-cell therapy do?

CAR T-cell therapy treatment modifies a patient’s T-cells to target and destroy cancer cells. It reprograms the immune system to recognise and attack specific cancer antigens, offering a personalised approach to cancer treatment that is particularly effective for certain blood cancers.

What is the success rate of CAR T therapy?

Success rates vary by cancer type and individual factors. For some blood cancers like acute lymphoblastic leukaemia, remission rates can reach up to 90%. For diffuse large B-cell lymphoma, response rates range from 40-60%. Ongoing research aims to improve efficacy for various cancers.

How much does CAR T cells cost?

CAR T-cell therapy is expensive. This cost covers the complex process of cell collection, modification, and reinfusion. Additional expenses may include hospital stays and managing potential side effects.

Who is eligible for CAR T-cell therapy?

Eligibility typically includes patients with certain relapsed or refractory blood cancers who haven’t responded to standard treatments. Factors like overall health, cancer type, and previous therapies are considered. As research progresses, eligibility may expand to include more cancer types.

How many days is CAR T therapy?

The entire CAR T-cell therapy process can take several weeks, from cell collection to post-treatment monitoring. The actual infusion of modified T-cells usually takes only a few hours, but patients require close monitoring for side effects for about 2-4 weeks afterwards.