AUNZ’s largest oncology research group, Breast Cancer Trials, today announced that their new trial for metastatic breast cancer patients called TUGETHER is recruiting participants.
Metastatic breast cancer is a devastating diagnosis where the cancer cells have spread from the original cancer site to other parts of the body. It can also be referred to as advanced breast cancer or Stage 4 breast cancer.
TUGETHER aims to find out if adding tucatinib and pembrolizumab to the usual treatment given to people with advanced HER2-positive breast cancer slows down the growth of the cancer.
In HER2-positive breast cancer, there are too many HER2 receptors on the surface of the cancer cell. Having too many receptors can cause the breast cancer cells to grow and divide very quickly. Anti-HER2 medicines (such as trastuzumab) slow or stop the growth of cancer cells by attaching to the HER2 receptor proteins on the surface of cancer cells and blocking the growth signals. Trastuzumab will be used in this study together with Tucatinib, which works in a different way to trastuzumab. Tucatinib gets inside the breast cancer cells and blocks the signals that are sent by the HER2 receptors. These two treatments complement each other to gain better control over the cancer cells.
Professor Sherene Loi is the Study Chair of the new TUGETHER trial which will involve 16 sites across Australia, is open to both men and women and will enrol 50 participants in the study.
“I am excited to use this medication to treat really hard to treat spots such as brain metastases, and that for these women is a real problem because often the spots in the brain are what shortens their life. Hopefully, we can prolong their life with this new medication combination,” Professor Sherene Loi,
Study Chair – TUGETHER Clinical Trial.
HER2 breast cancer is a type of breast cancer which tests positive for a protein called human epidermal growth factor receptor 2 (HER2). In HER2- positive breast cancer, there are too many HER2 receptors on the surface of the cancer cell. These HER2 receptors produce signals that tell the cell to grow and multiply and too many cause the breast cancer cells to grow and divide very quickly. This means it can be a faster growing type of breast cancer. Around 20% of all breast cancer cases are HER2-positive.
Pembrolizumab helps the immune system work against cancer by stopping a protein called PD-L1 (programmed cell death 1). The PD-L1 protein attaches to the surface of certain immune cells called T-cells, so the T-cells cannot find and kill cancer cells. Blocking PD-L1 can enable the immune system to find and kill cancer cells.
Increased levels of PD-L1 are referred to as “PD-L1 positive” and low levels of PD-L1 are referred to as “PD-L1 negative”. A sample of the tumour tissue provided at the start of the study will show if the cancer is PD-L1 positive or PD-L1 negative.
All trial participants will receive tucatinib, trastuzumab and pembrolizumab. Researchers know that pembrolizumab works well in many PD-L1 positive cancer types, but they don’t know how well it will work in PD-L1 negative breast cancer. PD-L1 negative participants will also be given capecitabine to give an extra layer of protection.
Capecitabine is used routinely in Australia to treat advanced breast cancer but it can cause side effects; researchers would like to avoid giving this to participants unless it is necessary, so PD-L1 positive participants will not receive capecitabine in this study. The researchers would like to find out if a new treatment program without capecitabine, and therefore one which avoids chemotherapy side effects, is effective in treating the cancer for PD-L1 positive participants.
Source: BCT
To find out more about the TUGETHER trial and Breast Cancer Trials’ work, access the website here.
