The discovery of pancreatic cancer biomarkers (naturally occurring molecules, genes or characteristics which can be used to confirm the presence or predict the outcome of a cancer) is vital in understanding patient outcomes and finding new therapeutic targets. In recent years, improved understanding of the biology of pancreatic cancers has resulted in new combination therapies being developed, including the development of the first successful biomarker-guided therapy in pancreatic cancer known as the POLO trial.
A recent paper from the SCALOP-1 trial team, led by Prof. Somnath Mukherjee, was published in BJC Nature, which has identified proteins that could act as a new biomarker to predict a patient’s outcome from pancreatic cancer. The chemokine protein known as CCL5, found circulating in patient blood, was found in low quantities in patients with better overall pancreatic cancer survival (around 18.5 months, rather than less than a year).
It is already known that CCL5 is involved in tumour invasion, tumour metastasis and the creation of an immune-system-suppressing micro-environment that allows pancreatic cancer to develop quickly. Its identification as a biomarker makes CCL5 a perfect new target for potential drug treatments. For example, blockade therapies that target the CCL5-CCR5 pathway and reduce the presence of CCL5, may produce new opportunities to improve the outcome of other immunotherapies that pancreatic cancer patients are undergoing.
Co-lead of this study, Prof Eric O’Neil from the Department of Oncology, is now investigating combination of CCL5 antagonist drugs with immunotherapy and radiotherapy drugs in animal models, which he hopes will lead to the development of new, more-effective pancreatic treatments in the future.
Next steps for the SCALOP trials
When pancreatic cancer has developed beyond a stage where it is operable, the only option for patients is often chemotherapy or chemoradiotherapy (the combination of chemo and radio therapy). The creation of new combination drugs used in the chemotherapy process has led to some improvement in overall length of patient survival of pancreatic cancer, which remains one of the highest causes of cancer death in the UK, however the use of these drugs is limited by the toxic effect on the body.
Following on from the SCALOP-1 trial, the SCALOP-2 trial, has been run from the University of Oxford, hosted through the Oncology Clinical Trials Office and lead by Prof Somnath Mukherjee. It has completed recruitment earlier in the year and final results are awaited.
Currently in the UK, chemoradiotherapy for locally advanced pancreatic cancer consists of 28 daily treatments of radiotherapy. Although this treatment is effective in controlling local symptoms and slowing down local cancer progression, in most cases it is unable to remove the cancer or shrink it well enough to make it operable. There is a need to find more efficient treatment combinations to improve patient outcomes.
The SCALOP-2 clinical trial compared different ways of combining chemotherapy and chemoradiotherapy to see which combination provides the most benefit to patients who have inoperable pancreatic tumours. This includes testing radiotherapy dose escalation and the use of nelfinavir as a radiosensitizer drug – something that makes tumour cells more sensitive to the effects of radiation therapy. In doing so, it is hoped that researchers can uncover more efficient drug combinations for patients with pancreatic tumours that are inoperable.
Blood and biopsy samples have been collected as a part of SCALOP-2 trial, in order to allow the team to take a more detailed look at proteins, DNA and cells involved in the cancer and how they are affected by treatment. This will tell researchers much more about how a patient’s type of cancer behaves and how it has responded to various treatments, allowing for the discovery of biomarkers just like CCL5 from the SCALOP-1 trial.
More information about the SCALOP-2 trial can be found on the Pancreatic Cancer UK website here.