The First Targeted Treatment for HER2-low Metastatic Breast Cancer

In the spirit of World Cancer Day this Saturday, February 4th, we are excited to see the recent Health Canada approval of Enhertu (trastuzumab deruxtecan) for another indication; to be the first targeted treatment for HER2-low metastatic breast cancer.

Currently, HER2 is classified as being positive or negative. However, approximately half of all breast cancers are HER2-low, which has limited treatments available. Until now, only those with HER2-positive breast cancer were eligible for HER2-targeted therapies, leaving those with lower expression of HER2 limited effective treatment options.

The pivotal DESTINY-Breast04 Phase III trial demonstrated Enhertu reduced the risk of disease progression by 49% and improved the median progression-free survival (10.1 mo vs. 5.4 mo) and overall survival (23.9 mo vs. 17.5 mo) compared to those randomized to chemotherapy.

Health Canada’s approval of Enhertu provides hope for patients with unresectable or metastatic HER2-low breast cancer to benefit from a directed therapy.

Written by Amber Hutchinson