Investigating how to improve immunotherapy for triple negative breast cancer

Research area: Better treatments

Professor Awen Gallimore is investigating ways to improve the effectiveness of immunotherapy for triple negative breast cancer. For this, she’s targeting multiple signals in breast cancer cells that work against the immune system. It could lead to new much needed treatments.

In this section

What's the challenge?

Triple negative breast cancers can be more aggressive than other types of breast cancer. They often respond to chemotherapy, but sometimes the disease can spread to other parts of the body within the first few years after treatment. It then becomes incurable.

Immunotherapy could help better treat these triple negative tumours, but it doesn’t work for everyone. We need to find ways to improve the effectiveness of immunotherapy so that more people with triple negative breast cancer can benefit from it.

Immunotherapy is showing enormous promise for treating cancer. However, current treatments only work well for a minority of patients with certain types of cancer. In the future we could have an immunotherapy treatment for triple negative breast cancer that’s effective for both early disease and secondary tumours. So, to get there, we want to test new ways to create anti-cancer immune responses and to examine how they work in primary and secondary disease.

Professor Awen Gallimore

What's the science behind the project?

In a previous Breast Cancer Now-funded project, Professor Awen Gallimore of the University of Cardiff and her colleagues found how we can partially turn on the immune system against triple negative breast cancer. For this, they were targeting immune cells, called regulatory T cells (or Tregs).

But they also discovered a new way that cancer cells keep the immune system ‘turned off’, called the LAG-3 signal. Blocking both the Tregs and the LAG-3 signal with drugs led to very strong immune reactions, which could stop secondary breast cancer cells growing. But this immune reaction was so strong that it also caused serious side effects.

Now, Awen is trying to tackle this problem in two ways. First, she wants to better understand how LAG-3 blocks the immune system inside cancers and how it can be targeted to boost immune responses without causing significant side effects.

Secondly, with the expertise of her colleague Professor Alan Parker, they are developing a therapy which uses cancer-seeking viruses. These could deliver drugs that block the LAG-3 signal directly in the tumour, leaving healthy cells intact.

Awen will test this in mice. This way, she’ll be able to see if blocking the LAG-3 signal causes a big enough immune response to get rid of both primary and secondary breast cancer cells without causing side effects.

What difference will this project make?

This project may give us a new treatment that can reduce the risk of triple negative breast cancer spreading to other parts of the body, where it becomes incurable. In short, it could help to save lives.

It’ll also allow us to better understand how breast cancer cells interact with the immune system, and in this way help us to develop new immunotherapies.

How many people could this project help?

Over 8,000 women diagnosed with triple negative breast cancer each year in the UK. Currently, about 1/3 of them will go on to develop incurable secondary breast cancer.