Closing in on a cure: Making cancer immunotherapy more effective

What if the cure for cancer was your own immune system? Lots of research has gone into making that a reality. The treatment is called immunotherapy, where your T cells are genetically modified to identify cancer cells and destroy them.

But this treatment is currently very expensive and time-consuming, so research has gone into making immunotherapy more accessible and more effective. In a recent study published in the journal Science Translational Medicine, a group of British scientists reportedly “cured” two infants of leukemia (cancer of the blood) using immunotherapy. Though the study has major limitations, it has shown a possible solution to working out the kinks of the treatment by using a new gene-editing technique called TALENS.

A closer look at immunotherapy

CAR T cell therapy is the type of immunotherapy that is being considered in the cancer community. It stands for chimeric antigen receptor T cell. The therapy involves removing some T cells (white blood cells that identify and kill invaders) from a patient’s blood. Those cells are genetically altered by adding special receptors on their surface called CARs. Then the cells are infused back into the patient’s blood. The receptors then seek tumour cells, attach to them and kill them. This treatment is only active in clinical trials, though some drug companies are planning to make the therapy available within a year.

This treatment has worked well with young leukemia patients. The down side? It’s costly and time-consuming. Each set of modified T cells needs to be custom-made for each patient. Sometimes patients don’t have enough healthy T cells to make this possible to begin with. Gene-editing solves some of these problems.

What’s new?

Gene-editing is the manipulation of genes in a person’s DNA. The recent study used a new gene-editing technique called TALENS. This makes the T cells universal, meaning that they can be used in any patient. Compared to custom-made T cells, making universal T cells reduces the time and money it takes to treat patients.

Gene-editing is also being used to get rid of obstacles that make CAR T cell therapy less effective. Researchers at the University of Pennsylvania are currently researching ways of using the gene-editing technique CRISPR to edit out two genes called checkpoint inhibitors that prevent CAR T cell therapy from working as well as it should. The upcoming trial will use human patients.