Trastuzumab Deruxtecan (Enhertu) Receives Breakthrough Therapy Designation in China for Second Indication in HER2-Positive Metastatic Breast Cancer

On April 1, the CDE website showed that AstraZeneca/Daiichi-Sankyo's HER2-targeted antibody-drug conjugate (ADC) Trastuzumab deruxtecan (T-DXd, Enhertu) for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have previously received one or more anti-HER2 therapies is proposed to be included in the breakthrough therapy designation.

This is the second indication for which the product has been granted Breakthrough Therapy Designation by the CDE. In December 2020, T-DXd monotherapy was awarded Breakthrough Therapy Designation by the CDE for the treatment of adult patients with HER2-positive locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received one or more prior treatment regimens.

On March 21 this year, T-DXd was submitted for marketing approval in China, with the indication unknown.

T-DXd is an ADC targeting HER2, designed using Daiichi Sankyo's proprietary DXd ADC technology. It consists of a HER2 monoclonal antibody linked to a topoisomerase I inhibitor payload (a derivative of exatecan) through a stable tetrapeptide cleavable linker. This product is the leading ADC in Daiichi Sankyo's oncology portfolio and also the most advanced project on AstraZeneca’s ADC scientific platform.

Enhertu was first approved for marketing by the US FDA in December 2019 based on the results of the Phase II DESTINY-Breast01 clinical study, for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior HER2-targeted therapies.

On January 15, 2021, the second indication was approved by the FDA for patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma who have previously received trastuzumab-based therapy.

On January 17 this year, the FDA also accepted the supplemental Biologics License Application (sBLA) for Enhertu to treat adult patients with unresectable or metastatic HER2-positive breast cancer who have previously received anti-HER2 therapy, and granted the application Priority Review status.