AstraZeneca and Daiichi-Sankyo are participating in a global collaboration to develop Enhertu (trastuzumab deruxtecan) for the treatment of HER2-low metastatic breast cancer (cancer that has spread). Enhertu is an ADC (antibody-drug conjugate). The ADC binds to certain markers on the cancer cell’s surface.
Currently, HER2 can be categorized as HER2 positive or HER2 negative. Some trial investigators, however, now use the term HER-2 low expression breast cancer, a term that describes cells and tissue that appear normal and spread slowly. HER2-low expression is found in HR-positive as well as HR-negative cancers.
HER2-positive cancer has a worse prognosis than HER2-negative, as it grows more rapidly and may spread to the lymph nodes. Chemotherapy is currently the only option for patients who are HR-positive if the cancer progresses after hormone (endocrine) therapy or for HR-Negative patients.
Breast cancer is responsible for over 685,000 deaths worldwide. In 2020 there were over two-million cases reported globally.
About the DESTINY-Breast04 Phase III Trial
Trial enrollment totaled approximately 540 patients in Asia, North America, and Europe. Information about the trial is available here.
DESTINY’s stunning results have rewarded patients with meaningful improvements in overall survival (OS) and progression-free survival (PFS) versus chemotherapy of physician’s choice.
- The secondary endpoint of PFS for HR-positive or HR-negative patients who have HER2-low metastatic breast cancer was met.
- OS endpoints were also met for HR-positive cancer patients.
There were no new concerns about Enhertu’s safety profile when compared to previous clinical trials.
Enhertu has been approved in over forty countries to treat patients with inoperable (unresectable) or HER2-positive metastatic breast cancer. These patients have been treated with a minimum of two prior anti-HER2 regimens in accordance with results from the DESTINY-Breast01 trial.
Plans are underway for further assessment of Enhertu for the safety and efficacy of HER2 cancers such as lung, gastric, breast, and colorectal cancers.
AstraZeneca’s V.P. of R&D in Oncology commented that DESTINY-Breast04’s historic news may reshape the classification and treatment of breast cancer. Further, she pointed out that this is the first time any HER2 therapy has proven to be beneficial for HER2-low metastatic breast cancer.
The company has the ambitious goal of eventually eliminating the fatal aspects of breast cancer.