Drug ‘dramatically improves’ outcomes for breast cancer

A new treatment for the most common form of breast cancer has boosted cure rates in a major international trial led by the Peter MacCallum Cancer Centre.

A new treatment for the most common form of breast cancer has boosted cure rates in a major international trial.

Results of the Peter Mac-led clinical trial showed that adding an immunotherapy drug to the chemotherapy that patients receive ahead of surgery “dramatically improved” breast cancer cure rates by as much as 20 per cent.

There were more than 500 women on the trial, most were from Victoria.

The women were newly-diagnosed with an early-stage and high-risk type of breast cancer which accounts for around 70 per cent of all breast cancer cases globally.

The researchers say the new treatment works as it seems a subset of this breast cancer contains high levels of immune cells which can be activated by immunotherapy to help kill cancer cells.

Oncologist Professor Sherene Loi led the international trial. Image: Supplied

Patients from 31 countries helped assess the impact of adding an infusion of the immunotherapy drug nivolumab – or a placebo – before surgery.

The Peter Mac’s Sherene Loi led the international trial called CheckMate-7FL and said the results were a really good outcome for patients.

“I think this study can help us use and finesse immunotherapy better for early-stage high risk hormone receptor breast cancer patients – this is the most common type of breast cancer in younger women,” Professor Loi said.

“We haven’t seen any new therapy increase the pathological complete response (pCR) in this group of breast cancer patients before. In this trial we observed a massive increase.”

The pCR means the lack of all signs of cancer in tissue samples after treatment.

Results of the trial showed that adding an immunotherapy drug to the chemotherapy that patients receive ahead of surgery “dramatically improved” breast cancer cure rates. Stock image.

Professor Loi said that longer follow up was needed to determine if this trial leads to more cures for high risk hormone receptor breast cancer.

“I think it will be clinically significant for these patients, but we do need to follow them long-term to see if it translates to event-free survival,” she said.

The results of the trial were published on Tuesday evening in Nature Medicine with the Peter Mac team describing them as potentially “practise-changing”.

The study was of patients with the most common form of breast cancer known as ER+/HER2, a type driven by hormones.

Oncologist Professor Loi said adding nivolumab saw almost double the number of patients achieved the best possible outcome of pCR.

“These patients are considered to be likely cured because their tumour was removed and samples of breast and lymph node tissue collected at the same time also show no detectable cancer cells,” Professor Loi said.

“The number of patients who achieved this pCR improved significantly as a result of nivolumab, an exciting result that points to a new treatment paradigm in this most common type of breast cancer.”

Professor Loi has been recognised for her work in breast cancer research and was awarded a Prime Minister’s Prize for Science in 2021 for her research into innovative treatments to improve the survival of breast cancer patients.

Originally published as Drug ‘dramatically improves’ outcomes for breast cancer