Context: The Indian firm ImmunoACT has received approval from the Central Drugs Standard Control Organization for its CAR-T cell therapy NexCAR19. The therapy is the first of its kind to be developed in India and will be used to treat certain types of cancers like B-cell lymphomas and leukaemia (blood cancer).
CAR-T cell therapy:
- Chimeric antigen receptor (CAR) T-cell therapy is a type of cell-based gene therapy which involves altering the genes inside T cells (a type of white blood cell) to help them attack cancer cells.
- In the therapy, T-cells are harvested from the patient’s blood.
- Researchers modify these cells in the laboratory so that they express specific proteins on their surface known as chimeric antigen receptors (CAR).
- These cells are then grown and multiplied in the laboratory and then inserted back into the patient.
- This genetic modification allows CAR T-cells to effectively bind to the cancer cells and destroy them.
CAR T therapy vs other cancer treatments:
Three major forms of treatment for any cancer are:
- Surgery (removing cancer)
- Radiotherapy (delivering ionising radiation to the tumour)
- Systemic therapy (administering medicines that act on the tumour, E.g., Chemotherapy, Immunotherapy)
- Conventional chemotherapy or immunotherapy comprises molecules that bind to the tumour or block chemical pathways that allow the tumour to grow or multiply – but do not directly affect the immune system. However, when there are abnormalities in the immune system or when the tumour finds a way to evade it, cancer resists these drugs.
- But, In CAR T-cell therapy, the immune system is activated when the modified T-cells are reintroduced into the body, which allows a gradual and sustained tumour kill as these cells multiply. As these cells are even more specific than targeted agents and directly activate the patient’s immune system against cancer, it makes the treatment more clinically effective.
Uses:
- CAR T-cell therapy has been approved for leukaemia (cancers arising from the cells that produce white blood cells) and lymphomas (arising from the lymphatic system).
- In certain kinds of leukaemia and lymphomas, the efficacy is as high as 90%, whereas, in other types of cancers, it is significantly lower.
- It is also used among patients with cancers that have returned after initially successful treatment or who have not responded to previous combinations of chemotherapy or immunotherapy.
Concerns:
- Potential side effects are also significant, associated with:
- Cytokine release syndrome (a widespread activation of the immune system and collateral damage to the body’s normal cells), and
- Neurological symptoms (severe confusion, seizures, and speech impairment).
- The complexity of preparing CAR T-cells has been a major barrier to their use. Also, the therapy involves considerable cost and skilled technical and human resources for its administration.
