AstraZeneca and Daiichi Sankyo's Enhertu (trastuzumab deruxtecan) has been approved in China as a monotherapy for the treatment of adult patients with unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer who have received a prior systemic therapy in the metastatic setting or developed disease recurrence during or within six months of completing adjuvant chemotherapy.
Enhertu is a specifically engineered HER2-directed antibody drug conjugate (ADC) being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.
The approval by China's National Medical Products Administration (NMPA) is based on the results of the DESTINY-Breast04 Phase III trial, first presented at the American Society of Clinical Oncology 2022 Annual Meeting and published in The New England Journal of Medicine.1 It follows the approval granted by China's NMPA for Enhertu in patients with previously treated unresectable or metastatic HER2-positive breast cancer in February 2023.
In China, breast cancer is the most common cancer in women, with more than 415,000 patients diagnosed in 2020.2 There were nearly 120,000 breast cancer deaths in China in 2020, representing around 18% of global breast cancer deaths.2 Approximately half of all breast cancers are considered HER2-low.3-5
Binghe Xu, MD, Director of the National Clinical Research Center for New Anticancer Drugs, Tenured Professor and Former Director, Department of Medical Oncology, Cancer Hospital Chinese Academy of Medical Sciences and Peking Union Medical College, said: "Historically, breast cancer tumours with low levels of HER2 expression have been classified as HER2-negative and have not been eligible for treatment with HER2-directed therapies. With this approval in China, based on the results of the DESTINY-Breast04 trial, clinicians will now be able to identify and potentially treat a distinct patient population based on HER2-low status."
Dave Fredrickson, Executive Vice President, Oncology Business Unit, AstraZeneca, said: "Patients with HR-positive or HR-negative, HER2-low metastatic breast cancer previously had few effective treatment options beyond chemotherapy. The results from the DESTINY-Breast04 trial show Enhertu provides a significant improvement in outcomes compared to chemotherapy for patients whose tumours are determined to be HER2-low via routine testing. This approval is an important advance in the way breast cancer is classified and treated in China and supports our vision to bring Enhertu to more patients worldwide."
Kiminori Nagao, Head of the Asia, South & Central America (ASCA) Business Unit, Daiichi Sankyo, said: "This approval of Enhertu for patients with HER2-low metastatic breast cancer, which comes shortly after the approval of Enhertu in patients with HER2-positive disease, marks the first time patients with HER2-low tumours will have the opportunity to be treated with a HER2-directed therapy. Enhertu now has the potential to become a new standard of care treatment option in China for a broad range of patients with HER2-expressing metastatic breast cancer."
In DESTINY-Breast04, Enhertu reduced the risk of disease progression or death by 50% versus physician's choice of chemotherapy (median progression-free survival [PFS] 9.9 vs. 5.1 months; hazard ratio [HR] of 0.50; 95% confidence interval [CI] 0.40-0.63; pEnhertu compared to chemotherapy with a median overall survival (OS) of 23.4 months in patients treated with Enhertu versus 16.8 months in those treated with chemotherapy.
The safety profile observed in patients treated with Enhertu in the DESTINY-Breast04 trial was consistent with that seen in other trials of Enhertu in breast cancer with no new safety signals identified.
