New results from the DESTINY-Breast03 Phase III trial showed that Enhertu (trastuzumab deruxtecan) demonstrated a higher progression-free survival (PFS) and objective response rate (ORR) in pre-specified patient subgroups compared to trastuzumab emtansine (T-DM1) in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane.
Enhertu is a HER2-directed antibody drug conjugate (ADC) being jointly developed by AstraZeneca and Daiichi Sankyo Company, Limited (hereafter, Daiichi Sankyo).
A similar PFS and ORR benefit was observed in exploratory analyses in patients defined by stable brain metastases, hormone receptor status, number of prior lines of therapy, prior pertuzumab treatment, or status of visceral metastasis. Results were presented in an oral presentation at the 2021 San Antonio Breast Cancer Symposium (SABCS).
Reinforce the potential of Enhertu
In patients with stable brain metastases at baseline, treatment with Enhertu resulted in higher PFS compared to T-DM1 (PFS by blinded independent central review (BICR) hazard ratio [HR] 0.25; 95% confidence interval [CI] 0.13-0.45). Additionally, in this subgroup, Enhertu improved PFS to a median of 15 months versus 3 months for T-DM1.
“More treatment options are needed to delay progression and extend survival for patients with HER2-positive metastatic breast cancer who develop brain metastases. These additional analyses from DESTINY-Breast03 reinforce the potential of Enhertu with similar benefits in the different subgroups,” says Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca.
Based on the primary results of DESTINY-Breast03, Enhertu received its fourth Breakthrough Therapy Designation (BTD) in the US for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received one or more prior anti-HER2-based regimens in September 2021.
Enhertu is approved for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in more than 30 countries based on the results from the DESTINY-Breast01 trial.
Enhertu is being further assessed in a comprehensive clinical development programme evaluating efficacy and safety across multiple HER2-targetable cancers, including breast, gastric, lung and colorectal cancers.
Photo of Susan Galbraith: AstraZeneca