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.
Where is it used?
- 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.
How widespread is its use?
- 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.
What are conventional cancer therapies?
- 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.
Will this therapy be expensive in India as well?
- 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.
