Note4Students

From UPSC perspective, the following things are important :

Prelims level: CAR T-Cell Cancer Therapy

Mains level: Not Much

cancer

The new CAR T-Cell Immunotherapy holds promise for Ovarian Cancer patients over other forms of treatment.

What are CAR T-cells?

Chimeric antigen receptor (CAR) T-cell therapies represent a quantum leap in the sophistication of cancer treatment.
Unlike chemotherapy or immunotherapy, which require mass-produced injectable or oral medication, CAR T-cell therapies use a patient’s own cells.
They are modified in the laboratory to activate T-cells, a component of immune cells, to attack tumours.
These modified cells are then infused back into the patient’s bloodstream after conditioning them to multiply more effectively.
The cells are even more specific than targeted agents and directly activate the patient’s immune system against cancer, making the treatment more clinically effective.
This is why they’re called ‘living drugs’.

How does the therapy work?

In CAR T-cell therapy, the patient’s blood is drawn to harvest T-cells which are immune cells that play a major role in destroying tumour cells.
Researchers modify these cells in the laboratory so that they express specific proteins on their surface, known as chimeric antigen receptors (CAR).
They have an affinity for proteins on the surface of tumour cells.
This modification in the cellular structure allows CAR T-cells to effectively bind to the tumour and destroy it.
The final step in the tumour’s destruction involves its clearance by the patient’s immune system.

As of today, CAR T-cell therapy has been approved for leukaemias (cancers arising from the cells that produce white blood cells) and lymphomas (arising from the lymphatic system).
These cancers occur through the unregulated reproduction of a single clone of cells, that is, following the cancerous transformation of a single type of cell, it produces millions of identical copies.
As a result, the target for CAR T-cells is consistent and reliable.
CAR T-cell therapy is also used among patients with cancers that have returned after an initial successful treatment or which haven’t responded to previous combinations of chemotherapy or immunotherapy.
Its response rate is variable. In certain kinds of leukaemias and lymphomas, the efficacy is as high as 90%, whereas in other types of cancers it is significantly lower.

The complexity of preparing CAR T-cells has been a major barrier to their use.
The first clinical trial showing they were effective was published almost a decade ago; the first indigenously developed therapy in India was successfully performed only in 2022.
The technical and human resources required to administer this therapy are also considerable.
Treatments in the US cost more than a million dollars.
Trials are underway in India, with companies looking to indigenously manufacture CAR T-cells at a fraction of the cost.
The preliminary results have been encouraging.

The three major forms of treatment for any cancer are surgery (removing the cancer), radiotherapy (delivering ionising radiation to the tumour), and systemic therapy (chemotherapy- administering medicines that act on the tumour only).
Surgery and radiotherapy have been refined significantly over time whereas advances in systemic therapy have been unparalleled.
A new development on this front, currently holding the attention of many researchers worldwide, is the CAR T-cell therapy.

In India, introducing any new therapy faces the twin challenges of cost and value.
Critics argue that developing facilities in India may be redundant and/or inappropriate as even when it becomes cheaper, CAR T-cell therapy will be unaffordable to most Indians.
Those who are affluent and require the therapy currently receive it abroad anyway.
While this is true, it may be the right answer to the wrong question.
Having access to a global standard of care is every patient’s right; how it can be made more affordable can be the next step.