Professor Arne Akbar
President, British Society for Immunology
Harnessing the immune system to treat cancer has seen much success, but challenges remain. How can we create the right environment to maximise its life-saving potential for patients?
Immunology has flourished in recent years, with new discoveries allowing us to understand its extensive involvement in maintaining health and the consequences that occur when these processes go awry.
This is particularly true in the field of cancer where the advent of immunotherapy has given new hope to patients and captured the imagination of doctors and scientists.
Immunotherapy was first explored in 1891
The first suggestion that the immune system might play a role in treating cancer came as early as 1891, when the surgeon, William Coley, treated a patient with a tumour on his tonsil by injecting it with bacteria to elicit an immune response.
The tumour began to break down and the patient lived for another eight years, showing that localised activation of the immune system could combat malignancy.
Unleashing the immune system to attack tumours
More recently, our understanding of how to harness the immune system to treat cancer was significantly accelerated by Jim Allison and Tasuku Honjo.
They discovered that the PD-1 protein acts as a ‘brake’ on immune cells, stopping them from attacking normal cells. Cancer cells hijack this mechanism to hide from the immune system.
By using a checkpoint inhibitor to block the interaction of PD-1 with PD-L1 expressed on cancer cells, the immune system can be unleashed to attack tumours.
Other areas of cancer immunotherapy have also hailed significant successes in recent years; including the use of another checkpoint inhibitor known as Ipilimumab (anti-CTLA4) in conjunction with Pembrolizumab (anti-PD-1) to treat melanoma.
The use of engineered chimeric antigen receptor (CAR) expressing T lymphocytes to treat some leukaemias and lymphomas has also proved revolutionary for a subset of patients, achieving high levels of remission in those who previously had few therapeutic options.
Immunotherapy doesn’t work for brain, prostate or pancreatic cancers
However, the story of cancer immunotherapy is not one of unmitigated success. Despite the hype, existing immunotherapies don’t work for many patients and numerous questions remain unresolved.
Some trials that initially carried great hopes led to patients developing unforeseen and, in some cases, serious side-effects. Furthermore, current immunotherapy approaches don’t work for some cancer types, such as brain, prostate or pancreatic.
Collaboration to drive research forward
We must promote interaction between researchers and clinicians in the field to facilitate translational research activity. The UK has all the ingredients needed, including infrastructure, investment and skills, to allow cancer immunology research to thrive.
The British Society for Immunology recently launched a new partnership with the National Cancer Research Institute to bring immunologists, cancer scientists and clinicians closer together.
By joining forces, we aim to facilitate dialogue between these groups to drive forward new collaborations that address challenges in immuno-oncology and advance understanding of the complex interactions between cancer and the immune system.
Establishing these links to speed up discovery in the clinical research space will enable fresh thinking to refine approaches on how to harness the immune system to target individual cancers.
Knowledge sharing is also a key part of the initiative, allowing oncologists to keep up to date with the latest thinking on how immunotherapies work and how they cause side-effects.
This will allow doctors to treat, not just the symptoms of these side effects, but also target the cause, hopefully leading to more effective therapies.
With over 350,000 new cases of cancer diagnosed in the UK each year, it is imperative that we move quickly to translate our endeavours into life-saving outcomes.
We must break down barriers of communication between research communities to deliver the transformative potential of immunotherapy to more patients living with cancer.