A new form of immunotherapy could delay resistance to hormone therapy

Grant information

Institution – University of Sheffield
Researchers – Professor Claire Lewis and Professor Janet Brown
Grant award - £397,398
Duration of funding – 2017-2024
Status - Complete
Reference – RIA16-ST2-022

Why did we fund this project?

• Immunotherapy encourages the body’s own defence mechanism - the immune system - to target cancer cells, either alone or with other treatments.  Immunotherapy has been successful in other types of cancer but has not yet been shown to be effective in prostate cancer.
• Hormone therapy is a powerful prostate cancer treatment, but some tumours develop resistance to the treatment and the cancer may spread to other parts of the body.
• Professor Lewis and her team wanted to encourage the immune system to target prostate cancer cells during hormone treatment.  They hoped this might extend the length of time the hormone treatment was effective.

What did the team do?

• The team used samples of human and mouse prostate tumours to show that immune cells called macrophages accumulate around tumour blood vessels after hormone therapy.
• The macrophages gather in large numbers just before the development of resistance to hormone therapy.
• The team then used microscopic carriers called lipid nanoparticles to deliver a drug specifically to these macrophages in prostate tumours. 

What did the team achieve?

• The team found that the drug stimulated the macrophages to release a chemical message to other immune cells - called T-cells – that were inside the tumour.
• When the T-cells inside the tumour received the chemical message from the surrounding macrophages, the T-cells were activated to kill prostate cancer cells.
• Excitingly, the team discovered that when this new form of immunotherapy was given at the same time as hormone treatment in mouse models, the development of resistance was delayed.

What does this mean for men?

• Activating the immune system to kill cancer cells is a promising step towards immunotherapy-based treatments for men with prostate cancer.
• Combining immunotherapy with hormone therapy could give men more valuable time before their cancer becomes resistant to hormone treatment.
• This approach could reduce the need for additional treatments such as radiotherapy or chemotherapy and help extend the lives of men with prostate cancer.