Enhertu Improves Overall Survival in HER2-Positive Metastatic Breast Cancer

AstraZeneca and Daiichi Sankyo have released updated results from the DESTINY-Breast03 Phase III trial, showing that Enhertu (trastuzumab deruxtecan) achieved a statistically significant and clinically meaningful improvement in overall survival (OS) compared to trastuzumab emtansine (T-DM1).

The study focused on patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane. The updated analysis revealed a 36% reduction in the risk of death for patients treated with Enhertu versus T-DM1. At two years, an estimated 77.4% of patients were alive in the Enhertu arm, compared to 69.9% in the T-DM1 arm.

Furthermore, Enhertu also demonstrated a significant improvement in progression-free survival (PFS), with median PFS showing a 22-month improvement over T-DM1. The objective response rate was 78.5% with Enhertu compared to 35.0% with T-DM1.

These findings, presented at the 2022 San Antonio Breast Cancer Symposium (SABCS), reinforce Enhertu's role as a potential new standard of care for patients with HER2-positive metastatic breast cancer in the second-line setting.