What is TIL therapy?

TIL (tumour-infiltrating lymphocyte) cell therapy uses the capabilities of the immune system to fight cancer. These infiltrating lymphocytes are the patient's immune cells found in the tumour tissue.

TIL therapy consists of recovering the functionality of the lymphocytes found in tumours, growing them in the laboratory then re-administering them to the patient. 

The lymphocytes in tumours are often inactive or in quantities too small for the tumour cells to be eliminated effectively; consequently, the tumours continue to grow.

TIL therapy requires a prior biopsy of the tumour to obtain infiltrating lymphocytes. These infiltrating lymphocytes are the patient's immune cells found in the tumour tissue. Consequently, one of the main limitations of this treatment is that the patient needs to have an accessible lesion to obtain the biopsy.

The first step in TIL therapy is a biopsy to obtain tumour-infiltrating lymphocytes. A series of techniques are then performed on the biopsy sample to obtain the smallest possible fragments; a cell culture is then performed and the reactive lymphocytes selected. After this step, they are multiplied in a bioreactor for 14 days. The cells obtained are those infused into the patient.