Enhertu reduced the risk of disease progression or death compared to chemotherapy in certain patients with metastatic breast cancer.
Daiichi Sankyo and AstraZeneca’s breast cancer treatment, trastuzumab deruxtecan – also known as Enhertu – has been evaluated in the DESTINY-Breast04 study. The treatment duly met the primary endpoint of progression-free survival in patients with hormone receptor-positive disease.
Detailed positive results from the phase 3 trial showed that trastuzumab deruxtecan demonstrated clinically meaningful progression-free survival and overall survival. The positive results involved previously treated patients with HER2 low unresectable and/or metastatic breast cancer with HR-positive or HR negative disease compared with chemotherapy.
In the primary endpoint analysis for DESTINY-Breast04, the drug demonstrated a 49% reduction in the risk of disease progression or death. An average survival of 10.1 months was seen in patients compared to 5.4 months with chemotherapy, as assessed by blinded independent central review.
Among all patients, the median progression-free survival was 9.9 months in the trastuzumab deruxtecan group and 5.1 months in the chemotherapy group.
“These results have the potential to redefine how metastatic breast cancer is classified and treated by improving our understanding of HER2 as a spectrum in breast cancer. They offer a potential new treatment option for an estimated 55% of breast cancer patients traditionally classified as HER2 negative, who could benefit from a HER2 targeted therapy,” explained Professor Peter Schmid from Barts Cancer Institute.
“Understanding the HER2 biomarker is helping us to deliver new cancer medicines for patients with high unmet needs. As such, these results demonstrate how HER2-directed therapies can benefit patients with HER2-low metastatic breast cancer. We will continue to work with the MHRA, NICE and NHS England around authorisation and access to treatment for this eligible patient population,” added Arun Krishna, head of oncology at AstraZeneca UK.
Haran Maheson, head of oncology at Daiichi Sankyo UK, added: “The DESTINY-Breast04 trial is the first-ever study to show the benefits of a HER2-directed therapy in patients with metastatic breast cancer with lower levels of HER2 expression. The DESTINY-Breast04 trial demonstrates how trastuzumab deruxtecan could provide a new treatment option for this patient population.”
Breast cancer remains the most common type of cancer affecting women in the UK, with 87.7 cases per 100,000 people.