A screening for breast cancer (Stock image)
(Picture: PA Archive)Scientists have hailed a “landmark moment” in the treatment of advanced breast cancer after a new drug was shown to slow the growth of the disease.
Capivasertib was found to double the amount of time people have the disease before it progresses in a clinical trial, potentially benefitting up to 8,000 women every year.
A phase III clinical trial of capivasertib alongside hormone therapy suggests the combination could become the new treatment for patients with advanced forms of the most common type of breast cancer.
The findings, presented at the San Antonio Breast Cancer Symposium on Thursday, relate to oestrogen receptor (ER) positive, human epidermal growth factor receptor 2 (HER-2) negative breast cancer.
Capivasertib works by blocking activity of the cancer-driving protein molecule AKT.
All of the trial’s participants had seen their cancer recur or progress on standard hormone treatments. The majority had already been treated with CDK4/6 inhibitors – drugs that block cancer cells from multiplying.
Patients whose cancer progresses generally receive fulvestrant hormone therapy. However, when this is not effective they are often left only with the option of chemotherapy.
Adding capivasertib to fulvestrant was found to shrink tumours in 23 per cent of patients, compared with 12 per cent of patients who received a placebo along with fulvestrant. It also doubled the median time of the progress of the disease from 3.6 months to 7.2 months.
As part of the trial, 355 patients received capivasertib plus fulvestrant and 353 patients received a placebo plus fulvestrant.
The new drug regime was also more effective for the four in 10 patients whose cancers had mutations to the AKT signalling pathway, with 29 per cent seeing their tumours shrink compared to 10 per cent on the placebo combination.
Genetic alterations to the AKT pathway can drive both cancer’s development and resistance to treatment.
Trial leader Nick Turner, professor of molecular oncology at the ICR and consultant oncologist at the Royal Marsden, said: “This is a fantastic finding for patients with breast cancer.
“Even with the best current treatments, people with this type of advanced breast cancer will eventually see their cancer stop responding to treatment, and it will progress.
“We’re delighted that this potential first-in-class drug combined with hormone therapy can lower the progression of these advanced cancers, and in almost a third of cases can shrink tumours.
“We believe this new treatment could allow more women and men to live well and live longer with breast cancer.”
Professor Kristian Helin, chief executive of the ICR, said: “This is a landmark moment for the treatment of advanced forms of the most common type of breast cancer.
“Capivasertib could offer a completely new treatment option for these patients.
“This is a major success story for UK science – the discovery and development of capivasertib showcases the benefits of collaboration between academia, charities and industry to bring game-changing new treatments to people with cancer as quickly as possible.”
Linda Kelly, 65, from Milton Keynes, joined the trial at the Royal Marsden in August 2021 after her breast cancer spread to her bones and chest wall.
She said: “The results have been amazing. There has been a substantial reduction in my disease, my cancer has not progressed, and I haven’t had any new tumours.
“The treatment is far less debilitating than chemotherapy and I’ve been given the gift of a longer life.”
Capivasertib is being manufactured by pharmaceutical giant AstraZeneca following a programme of drug discovery research at the Institute of Cancer Research (ICR) in London.
The trial was led by researchers at the ICR and the Royal Marsden NHS Foundation Trust.
