CAR-T Cell Therapy

CAR-T CELL THERAPY

Why in news?

The Central Drugs Standard Control Organisation (CDSCO) has approved NexCAR19, an Indian CAR-T cell therapy developed by ImmunoACT, an IIT Bombay incubated company.

What is CAR-T Cell Therapy?

• CAR-T cell therapy modifies T-cells into potent cancer fighters.
• T-cells are a type of white blood cell that typically fights infections.
• In CAR-T therapy, these T-cells are genetically modified to target cancer. This makes them more effective, and they are called “living drugs.”

How Do CAR-T Cells Kill Cancer Cells?

1. The therapy is made to attack cancer cells with the CD19 protein. This protein acts as a marker on cancer cells, allowing CAR-T cells to identify and attach to them, starting the process of eliminating the cancer.
2. They primarily target and destroy cancer cells, particularly in blood cancers like leukaemia and lymphomas.

Mechanism:

1. Collection: T cells (a type of immune cell) are extracted from the patient’s blood through a process called leukapheresis.
2. Genetic modification: In the laboratory, these T cells are genetically engineered to express a chimeric antigen receptor (CAR) specific to a protein found on the surface of cancer cells.
3. Expansion: The modified CAR-T cells are cultured and expanded to create a large population of these specialized cells.
4. Infusion: The expanded CAR-T cells are then infused back into the patient’s bloodstream.
5. Targeting cancer cells: The CAR on the surface of these engineered T cells allows them to recognize and bind to the cancer cells that express the corresponding antigen.
6. Activation: Once bound to the cancer cells, the CAR-T cells become activated and initiate an immune response against the cancer cells.
7. Killing cancer cells: The activated CAR-T cells release cytotoxic substances and trigger an immune response, leading to the destruction of the cancer cells.
8. Persistence: Some CAR-T cells may persist in the patient’s body, providing long-term surveillance and potential protection against cancer recurrence.

The benefits of CAR-T cell therapy:

1. High efficacy in treating certain blood cancers.
2. Targeted treatment with minimal harm to healthy cells.
3. Potential for long-lasting protection.
4. Curative potential.
5. Personalized for each patient.
6. Reduced need for chemotherapy.
7. Ongoing research for broader applications.

Issues and Challenges associated with CAR-T cell therapy:

1. Severe Immune Response: CAR-T therapy can trigger a strong immune response called CRS, which can be very harmful.
2. Brain and Nervous System Effects: Some patients may experience confusion or seizures.
3. Limited Use: It’s currently only approved for specific blood cancers, not solid tumours.
4. High Cost: It’s often very expensive and not affordable for many patients.
5. Complex Manufacturing: Making CAR-T cells is complex and time-consuming, causing treatment delays.
6. Unknown Long-Term Effects: We’re still learning about the therapy’s long-term results.
7. Target Loss: Some cancer cells can lose the CAR-T target, reducing its effectiveness.
8. Overactive Immune Response: Sometimes, the immune system can harm healthy tissues due to its aggressiveness.
9. Limited Access: Not all hospitals provide CAR-T therapy, and it’s not widely available.
10. Ongoing Research: More studies are needed to treat a wider range of cancers and make CAR-T therapy safer and better.

TERMINOLOGY:

Central Drugs Standard Control Organisation (CDSCO):

The Central Drugs Standard Control Organisation (CDSCO) is India’s national regulatory body for cosmetics, pharmaceuticals and medical devices. It works under Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India.

Chimeric antigen receptors (CARs):

CARs are special receptors that change how T cells work. They help T cells target specific things in the body’s immune response.

T-Cells:
T cells, or T lymphocytes, are white blood cells which are crucial for the immune response.

There are two primary types: Helper T cells and cytotoxic T cells.

1. Helper T cells support other immune cells.
2. Cytotoxic T cells are responsible for killing virally infected cells and tumours.