13 October 2021

A new study funded by Breast Cancer Now will explore if the drug talazoparib (Talzenna) could be used to treat people with incurable secondary (metastatic) breast cancer which has spread to the brain.

Secondary breast cancer occurs when breast cancer cells spread from a primary tumour in the breast, through the lymphatic or blood system to other parts of the body where it becomes incurable. There are limited treatment options for people with breast cancer that has spread to the brain and a lot of drugs are unable to reach these tumours because of the brain’s natural protection, meaning new treatment discoveries are urgently needed.

Talazoparib is an existing PARP inhibitor drug which works by preventing cancer cells with altered BRCA genes from repairing their DNA, forcing them to die. Although the drug is licensed for use in certain patients with BRCA mutated, HER2 negative locally advanced or secondary (metastatic) breast cancer, it hasn’t been assessed for use on the NHS.

Now, a team led by Professor Leonie Young and Dr Damir Vareslija from RCSI University of Medicine and Health Sciences will investigate if the drug could be used to treat secondary breast cancer in the brain.

Through previous research, which analysed tumour samples donated by people whose breast cancer has spread to the brain, the team established that almost half of the tumours had changes in the way they repair their DNA and this could make these tumours vulnerable to PARP inhibitors like talazoparib.

Using tumours and breast cancer cells donated by patients, researchers will now test in the lab if talazoparib is effective in treating secondary breast cancer in the brain. Through further tests using mice and sophisticated laboratory models mimicking the brain’s protective system, the researchers will see if the drug can also reach tumours in the brain. The researchers aim to identify key features of a tumour that responds to this type of treatment to establish who could benefit most.

The study is being funded by the Breast Cancer Now Catalyst Programme, which aims to accelerate progress in world-class breast cancer research through innovation and collaboration. As part of the Programme, Pfizer have provided Breast Cancer Now with funding through an independent medical research grant and given the charity’s researchers access to several Pfizer medicines.

Professor Leonie Young, Professor in the Department of Surgery at RCSI University of Medicine and Health Sciences said:

“Our previous research has shown that, in many cases, secondary breast cancer tumours in the brain have changes in the way they repair their DNA and we believe this could make them vulnerable to PARP inhibitor drugs like talazoparib.

“People are always at the heart of the research we do and we are always trying to answer questions that are important to our patients. The support of Breast Cancer Now will enable us to learn more about the effectiveness of these powerful drugs to hopefully treat people with secondary breast cancer which has spread to the brain in the future.”

Dr Simon Vincent, Director of Research, Support and Influencing at Breast Cancer Now, said:

“An estimated 35,000 people in the UK are living with incurable secondary breast cancer, and the fear and uncertainty around when this devastating disease will cut their lives short. We desperately need to discover new ways to treat this incurable disease, including for those whose breast cancer has spread to the brain and who have very limited treatment options.

“That’s why we’re delighted, this Secondary Breast Cancer Awareness Day, to announce that we’re funding Professor Young’s project through The Breast Cancer Now Catalyst Programme. We hope this study will be successful and lead to effective new treatments for those who badly need them.”

Natalie Woodford, 57, mother of one from Surrey, was diagnosed with secondary breast cancer in 2017. In 2018 she was told her cancer had spread to her brain. Natalie said:

“I had primary breast cancer 10 years before my secondary diagnosis. After seeking help from my oncologist for severe pains in my neck and shoulders, I was diagnosed with secondary breast cancer in my bones and lungs. I was devastated. Then in 2018 I woke up with pains down my left-hand side and went straight to hospital. I was told that the cancer had spread to my brain.

“I’ve been very open about my situation with my husband and our 21-year-old daughter, as well as our family and friends. All of them support me in their own way, but know not to fuss me and understand my need to get on with things. My husband drives me around now as I am not allowed, which enables me continue to go to the theatre and art exhibitions and to see my family and friends. He does a lot for me, and we generally do more together, which feels good.  

“It’s really encouraging to learn about the new secondary breast cancer research happening. I hope that this study will be a success and lead to new treatments for women like me in the future.”

October is Breast Cancer Awareness Month. By accelerating world-class breast cancer research and providing vital support Breast Cancer Now is finding a way forward for everyone affected by breast cancer, every way they can.

The Catalyst Programme is accelerating progress in breast cancer research through 28 innovative breast cancer research projects, including clinical trials, which are taking place across the UK and Europe. All of these projects aim to bring better outcomes for people affected by breast cancer.

For more information on The Breast Cancer Now Catalyst Programme visit: breastcancernow.org/catalyst