Institution: Institute of Cancer Research
Project title: Developing a preclinical and clinical system for oncolytic virotherapy using isolated limb perfusion
Researchers: Dr Kevin Harrington and Dr Tim Pencavel
Grant award: £30,014
Duration: 2009 - 2011
This is an example of a translational research project, looking at ways to transfer results from the laboratory into a clinical trial in patients in a Phase 1 Trial. They are developing a system for treating limb sarcomas using Isolated Limb Perfusion (ILP) as well as oncolyic virotherapy (anti-cancer viruses)
ILP is used for sarcomas that can’t be removed by surgery because of their size or because they are close to vital structures such as blood vessels or nerves. During ILP the main blood vessels to the limb are identified and connected to a bypass machine to create a circuit. Fluid consisting of blood and an artificial plasma like fluid is then passed round this circuit. Chemotherapy can be added to the fluid, along with a naturally occurring human protein called tumour necrosis factor-alpha - TNFa - which makes the tumour blood vessels leaky. This means the amount of chemotherapy getting into the tumour through leaky blood vessel walls is higher than is usually possible, meaning treatment is more effective.
Oncolytic viruses infect tumour cells and replicate in them to a much greater extent than in normal cells. As part of their life cycle oncolytic viruses can lyse or burst tumour cells causing cell death. Once this bursting has occurred the immune system recognises not only the virus particles but components of the tumour cells. This leads to the immune system being able to destroy cancer cells that have not been exposed to the virus.
On the basis of results from several studies these viruses are now tested in humans with advanced cancer. However, then the viruses are put into human circulation much of their potency is lost because low numbers of viral particles reach the tumour, having been sieved out by the liver and spleen or held up by the immune system.
ILP with added TNFa may be the way to ensure that more anti cancer viruses reach the tumour, hence improving treatment.
They are doing a series of animal studies to test the effects of ILP combined with oncolytic virotherpy (anti cancer viruses) against sarcomas. They will measure how effective this is against the primary tumour and see how the treatment might be able to tackle sarcoma that has spread to other sites in the body.
They are hoping to use the results to move on to designing a Phase 1 trial.