Professor of Molecular Pathology, University of Limerick
Lecturer in Immunology, University of Limerick Health Research Institute
Immunotherapy is offering a new dimension to cancer treatment but a major challenge facing scientists and clinicians is knowing which patients will respond well to it.
The fight against cancer is constantly evolving with rapid developments in treatment underpinned by ground-breaking research.
A more recent innovation has been immunotherapy, a technique which helps the human body stage its own fightback against disease, in contrast to chemotherapy which introduces toxic elements to kill cancer, often with significant side effects.
While being used more frequently in clinical settings, it remains unclear which patients will, and will not, respond to immunotherapy.
Utilising the immune system
That challenge is being addressed by research at the Health Research Institute at the University of Limerick in Ireland where immunologists are focussing on cells in the immune system and how they function.
Immunologist Dr Elizabeth Ryan explains that immunotherapies are about reactivating the patient’s own immune system but emphasised that tumours in different organs – whether melanoma, lung cancer or colon cancer – have different mutations.
Working on colon cancer and why some tumours are richly infiltrated with immune cells and others have no immune cells, she adds: “By understanding what drives the different immune profiles in the microenvironment we can begin to sort these patients into groups to stratify them into potential responders to different types of therapies.”
Noting that the tumour microenvironment is dynamic with cells flowing through it, she says: “That means it can be very difficult to take a snapshot in time and use that to predict the presence of something at a timepoint in the future.”
We can use drugs to unleash a pre-existing immune response to the cancer cells.Paul Murray
Professor of Molecular Pathology Paul Murray’s team is using patient samples to look at changes in the tumour microenvironment to predict responses to immunotherapy.
He says there are different types of immunotherapies, such as immune checkpoint inhibition, which reactivate the immune response that has been silenced in the cancer.
“We can use drugs to unleash a pre-existing immune response to the cancer cells. The problem is that we do not know why some patients respond well,” he adds.
No one size fits all
What is clear is that there is not a single immunotherapy that is effective for all patients.
The holy grail is to identify biomarkers for drugs but even when you have a drug which targets a particular protein, it is still not clear which patients will respond well, says Professor Murray.
Boosting the team’s chances of success is the use of CODEX technology, which allows researchers to map the different components of the tumour microenvironment.