Modern immunotherapy

Immunotherapies aim to improve the immune response to a cancer that a patient’s immune system had previously failed to target.

Main categories include:

• Monoclonal antibodies
• CAR-T cells
• Checkpoint inhibitors
   

Limitations of modern immunotherapy
Modern immunotherapies are based on defined targets that are not unique to a patient's cancerous cells. 

For instance monoclonal antibodies and CAR-T cells are not based on cancer specific molecules. Their clinical effect thus depends on the presence of this molecule in a patient’s to be treated tumour whereas side effects will depend on their abundance on healthy cells. Both the efficacy and side effects of these therapies will therefore vary per individual patient and all will not be effective against tumour cells that do not express the targeted molecule. 

Similarly checkpoint inhibitors do not target a cancer specific checkpoint but checkpoints that are also expressed on healthy cells. Their efficacy thus depends on how a patient's cancer cells have happened to avoid an immune response but they can result in severe side-effects as a result of undesired auto-immune reactions. 

This therefore presents a fundamental difference compared to naturally occuring immune responses to tumours; these are very tumour specific and will not result in side effects resulting from auto-immune reactions.