AstraZeneca (AZ) and Daiichi Sankyo have shared positive results from a phase 3 trial on the use of Enhertu (trastuzumab deruxtecan) in the treatment of patients with HER2-positive metastatic breast cancer.
The 600-patient phase 3 DESTINY-Breast02 trial compared Enhertu against a treatment pre-determined by physicians in people with HER2-positive metastatic breast cancer.
The trial evaluated a similar breast cancer patient population as the DESTINY-Breast01 phase 1 trial, which was the basis for initial approvals in Europe and several other countries, AZ said.
DESTINY-Breast02 demonstrated a ‘statistically significant and clinically meaningful improvement in progression-free survival’ in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab emtansine.
The trial also met the key secondary endpoint of improved overall survival (OS), and the safety profile of Enhertu was consistent with previous phase 3 clinical trials with no new safety concerns identified.
Breast cancer is one of the leading causes of cancer-related deaths globally, with more than two million cases diagnosed in 2020, resulting in nearly 685,000 deaths worldwide. Approximately one in five patients with breast cancer are considered HER2-positive.
Enhertu belongs to a class of therapies called antibody drug conjugates (ADC), and consists of a HER2 monoclonal antibody chemically linked to a cell-killing chemotherapy drug.
Commenting on the positive results, Ken Takeshita, global head of R&D, Daiichi Sankyo, said: “The top-line results from DESTINY-Breast02 confirm the robust progression-free survival seen in previous trials of Enhertu and enrich our clinical understanding of the benefit this therapy may offer patients with HER2-positive metastatic breast cancer.
“As this is the confirmatory trial for our current breast cancer indication in Europe and several other countries, we look forward to sharing these findings with regulatory authorities to add to the body of data for Enhertu for the treatment of HER2-positive metastatic breast cancer.”
The announcement follows the approval of Enhertu by the US Food and Drug Administration (FDA) earlier this month for the treatment of adults with unresectable or metastatic breast cancer expressing low levels of HER2, a newly defined subset of HER2-negative breast cancer.
Also in August, Enhertu received FDA approval to treat adults with unresectable or metastatic non-small cell lung cancer (NSCLC), whose tumours have activating HER2 mutations.