The billions of TILs that have been grown in the laboratory will be given back to the same patient by giving an infusion into a vein (i.e. in the arm). The high numbers of TILs circulating in the patient’s body are thought to help their immune system fight the melanoma more effectively, as there will be a higher number of TILs that are available to find, attack and kill the melanoma cells.

This method is known as ‘autologous’, which means that the TILs are given back as treatment to the same patient from which the melanoma cells were originally taken.

TIL therapy is a one-time treatment. After receiving the infusion of TILs the patient will receive some immune-modulating treatment called IL-2 as an infusion (i.e.into a vein in the arm) for a number of days. This treatment is to help stimulate the immune system and the TIL activity in the body.

For the duration of their stay doctors will monitor patients for any side effects or reactions to the therapy at each stage of the treatment process to ensure that they are well before they can go home.

What is the treatment process for cNeT therapy?

After TILs have been grown to large numbers, and before they are introduced back into the body, researchers have found a way of testing in the laboratory to see if they have any action against the specific clonal neoantigens that the melanoma has. The cells that have this specific action are known as clonal neoantigens-reactive T-cells (cNeT) and they can be separated from the other TILs to make the therapy very highly specific to that patient’s melanoma. These extracted cNeT will be combined with a specific chemical to help them grow, resulting in billions of cNeT. These are then given back to that same patient through an infusion into the vein. The patient will follow the same treatment process before and after the cNeT infusion, as with the TIL therapy infusion.

What is the difference between cNeT and TIL therapy?

CNeT are thought to be more specific and therefore more active against melanoma than the conventional TIL therapy, as they specifically target the clonal neoantigens that are known to be on the surface of that patient’s melanoma cells. This makes the treatment more personalised towards the patient’s own melanoma because it uses the cNeT to find and kill the specific melanoma cells from which they were produced.

CNeT therapy is in the very early stages of research, and so researchers around the world still use both cNeT and TIL therapies in clinical trials to be able to gather enough evidence to prove how effective they both are against melanoma.

TIL and cNeT therapy are one-off treatments, but very intense. As well as looking at how effective these treatments are at treating melanoma, doctors are still studying how well patients cope with the therapy and what side effects they may experience during the whole treatment process.

There are currently some early phase trials in the UK looking at TILs and cNet therapy. You can have a look at the ones that are open to recruitment now on our Melanoma TrialFinder.