Enhertu approved in EU for HER2-low breast cancer

Enhertu (trastuzumab deruxtecan) has been approved in the European Union (EU) for adults with unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer. The approval is indicated for those who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within six months of completing adjuvant chemotherapy.

The antibody drug conjugate (ADC) is the first HER2-directed therapy for HER2-low metastatic breast cancer. It is being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.

DESTINY-Breast04 Phase III trial for Enhertu

The regulatory approval by the European Commission (EC) follows the positive opinion of the Committee for Medicinal Products for Human Use (CHMP).

In the DESTINY-Breast04 Phase III trial, the ADC reduced the risk of disease progression or death by 50 percent and increased overall survival by more than six months versus chemotherapy. This is based on a hazard ratio [HR] of 0.50; 95 percent confidence interval [CI]: 0.40-0.63; p<0.0001) in patients with HER2-low metastatic breast cancer with hormone receptor (HR)-positive or HR-negative disease.

The safety profile observed in the trial was consistent with that seen in other trials of Enhertu in breast cancer with no new safety signals identified.

The trial results were presented at the American Society of Clinical Oncology 2022 Annual Meeting and published in The New England Journal of Medicine.

Treating HER2-low breast cancer with a HER2-directed therapy

Dave Fredrickson, Executive Vice President, Oncology Business Unit, AstraZeneca shared: “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.”

Dr Javier Cortés, PhD, Head of the International Breast Cancer Center in Barcelona, Spain stated: “The [EC’s] approval marks the first time we will have the opportunity to treat patients with lower levels of HER2 expression with a HER2-directed therapy. Enhertu has shown… its potential to become a new standard of care.”

“This approval highlights the need to evolve the way breast cancer is treated to improve outcomes for patients,” concluded Fredrickson.