Vaccine That Wiped Out Cancer in Mice Ready for Human Trial
Channel: Tey Yomiko
Date: 03/02/2018

Vaccine That Wiped Out Cancer in Mice Ready for Human Trial

New York: Raising hopes for a cancer vaccine for different types of cancers, researchers have found that injecting minute amounts of two immune-stimulating agents directly into solid tumours in mice can eliminate all traces of cancer in the animals.

A clinical trial was launched in January to test the effect of the treatment in humans with lymphoma, cancer of the lymphatic system.

The approach works for many different types of cancers, including those that arise spontaneously, said the study published in the journal Science Translational Medicine.

The researchers believe the local application of very small amounts of the agents could serve as a rapid and relatively inexpensive cancer therapy that is unlikely to cause the adverse side effects often seen with bodywide immune stimulation.

"When we use these two agents together, we see the elimination of tumours all over the body," said senior author of the study Ronald Levy, Professor at Stanford University School of Medicine in the US.

"This approach bypasses the need to identify tumour-specific immune targets and doesn't require wholesale activation of the immune system or customisation of a patient's immune cells," Levy said.

"Our approach uses a one-time application of very small amounts of two agents to stimulate the immune cells only within the tumour itself. In the mice, we saw amazing, bodywide effects, including the elimination of tumours all over the animal," Levy explained.

Cancers often exist in a strange kind of limbo with regard to the immune system. Immune cells like T cells recognise the abnormal proteins often present on cancer cells and infiltrate to attack the tumour. However, as the tumour grows, it often devises ways to suppress the activity of the T cells.

Levy's method works to reactivate the cancer-specific T cells by injecting microgram (one-millionth of a gram) amounts of two agents directly into the tumour site.

One, a short stretch of DNA called a CpG oligonucleotide, works with other nearby immune cells to amplify the expression of an activating receptor called OX40 on the surface of the T cells.

The other, an antibody that binds to OX40, activates the T cells to lead the charge against the cancer cells.

Because the two agents are injected directly into the tumour, only T cells that have infiltrated it are activated. In effect, these T cells are "prescreened" by the body to recognise only cancer-specific proteins.

"This is a very targeted approach," Levy said.

"Only the tumour that shares the protein targets displayed by the treated site is affected. We're attacking specific targets without having to identify exactly what proteins the T cells are recognising," Levy added. 

Fighting cancer with nanobodies and computer simulations

Stimulating or enhancing someone's own immune system to fight cancer is not a new concept but scientists are taking it one step further by using nanoscience and computer simulations to improve existing treatments.

Immunotherapy drugs are specifically designed to help the immune system respond to cancerous cells, something that it doesn't naturally do. That's because cancer cells are essentially the body's own cells gone rogue and the immune system is programmed not to target native cells.

Now, a new computer simulation that mimics the body's response when exposed to certain immunotherapy drugs could speed up their development by eliminating any dud ideas at an earlier stage.

Scientists on the EU-funded MODICELL project have developed prototype software that can trial potential recipes for drugs by using a kind of graphic interface called reactive animation to demonstrate the body's expected response.

With the information gained from the simulation, the scientists can decide whether to pursue developing a potential drug or to go back to the drawing board, without wasting valuable time and resources.

'We wanted to develop a computerised approach that will allow us to simulate and to make predictions regarding immune responses that could be used to improve therapies against cancer or in-organ transplantations,' said Dr. Nuno Andrade of St. Anna Children's Cancer Research Institute, Austria, who managed the project.

To improve the accuracy of the simulations, the researchers first of all conducted real-life experiments in the laboratory and collected extensive biological information from published literature.

Computer scientists worked in the lab together with biologists to better understand the behaviour of the immune system, and used the knowledge gained to develop the computer simulation.

Dr. Andrade says this type of collaboration is likely to continue. 'Biology is such a complex science. There is no way that we can keep doing science without computerised approaches.'