Partners AstraZeneca (AZ, NASDAQ: AZN) and Daiichi Sankyo (TYO: 4568) have announced that their co-developed antibody drug conjugate (ADC), Enhertu (trastuzumab deruxtecan), has been granted a new indication approval in China. This marks the drug’s second approval in the country and is specifically for use as a monotherapy in treating adult patients with unresectable or metastatic HER2-low breast cancer who have been previously treated with metastatic disease or have experienced disease recurrence within six months of completing adjuvant chemotherapy.
DESTINY-Breast04 Trial Results Drive Approval
The latest approval is supported by the positive outcomes of the DESTINY-Breast04 Phase III trial. The trial demonstrated that Enhertu exhibited consistent efficacy in metastatic breast cancer patients, regardless of HER2 expression levels (IHC 1+ and IHC 2+/ISH-), and in patients who were HR positive or negative with low HER2 expression. The progression-free survival (PFS) analysis revealed that Enhertu reduced the risk of disease progression or death by 50% compared to physician’s choice of chemotherapy, with a median PFS of 9.9 months for Enhertu versus 5.1 months for chemotherapy (hazard ratio [HR] of 0.50; 95% confidence interval [CI] 0.40-0.63; p<0.0001) in all randomized patients with HER2-low metastatic breast cancer.
Enhertu Demonstrates Survival Benefits Over Chemotherapy
Furthermore, Enhertu showed a 36% reduction in the risk of death compared to chemotherapy, with a median overall survival (OS) of 23.4 months in patients treated with Enhertu versus 16.8 months in those treated with chemotherapy (HR of 0.64; 95% CI 0.49-0.84; p=0.001). These results underscore the potential of Enhertu as a significant treatment option for patients with HER2-low breast cancer, offering a new therapeutic approach in the fight against this disease.-Fineline Info & Tech
