AstraZeneca/Daiichi Sankyo’s Enhertu approved by EC for advanced breast cancer

AstraZeneca (AZ) and Daiichi Sankyo’s Enhertu (trastuzumab deruxtecan) has been approved by the European Commission (EC) to treat unresectable or metastatic HER2-low breast cancer.

Specifically, the HER2-directed antibody drug conjugate is indicated for adult patients who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within six months of completing adjuvant chemotherapy.

The approval, which follows a recommendation from the European Medicines Agency’s Committee for Medicinal Products for Human Use, is based on results from the DESTINY-Breast04 phase 3 trial.

The trial showed a reduction in the risk of disease progression or death by 50% in Enhertu-treated patients versus physician’s choice of chemotherapy in patients with HER2-low metastatic breast cancer with HR-positive or HR-negative disease.

Enhertu also demonstrated a median progression of 9.9 months versus 5.1 months in those treated with chemotherapy, as well as a 36% reduction in the risk of death.

Breast cancer is one of the leading causes of cancer-related deaths globally, with more than two millions cases diagnosed in 2020, resulting in nearly 685,000 deaths worldwide.

HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of many types of tumours including breast, lung, gastric and colorectal cancers, and is one of many biomarkers expressed in breast cancer tumours.

Dave Fredrickson, executive vice president of AZ’s oncology business unit, explained: “Historically, patients with breast cancer who have tumours with low levels of HER2 expression have been classified as HER2-negative, giving them limited treatment options beyond chemotherapy.

“This approval reinforces the important role Enhertu may have for patients with HER2-low disease and highlights the need to evolve the way breast cancer is treated to improve patient outcomes.”

Commenting further on the approval, Ken Keller, global head of oncology business, president and chief executive officer of Daiichi Sankyo, said: “This milestone also supports our vision to bring Enhertu to more patients across the HER2 spectrum, which requires a change to the breast cancer classification system that has been guiding treatment for more than two decades.”

Enhertu is also currently approved for this HER2-low breast cancer post-chemotherapy indication in more than 30 countries, as well as for the treatment of certain patients with HER2-positive breast cancer in over 40.

In addition to its indications in breast cancer, Enhertu has also been approved for gastric or gastroesophageal junction adenocarcinoma and non-small cell lung cancer.