WILMINGTON, Del.– The U.S. Food and Drug Administration has accepted and granted Priority Review to a supplemental Biologics License Application (sBLA) from AstraZeneca and Daiichi Sankyo for ENHERTU® (fam-trastuzumab deruxtecan-nxki) in combination with pertuzumab as a first-line treatment for adult patients with unresectable or metastatic HER2-positive breast cancer.
The review is based on results from the Phase III DESTINY-Breast09 trial, which showed that ENHERTU plus pertuzumab reduced the risk of disease progression or death by 44 percent compared to the current standard of care regimen of a taxane, trastuzumab and pertuzumab (THP). Patients receiving the ENHERTU-based regimen achieved a median progression-free survival of more than 40 months versus 26.9 months for THP.
“The DESTINY-Breast09 trial showed that treating patients with HER2-positive metastatic breast cancer with ENHERTU in combination with pertuzumab until progression in the first-line setting produced a new landmark of more than 40 months for progression-free survival and nearly doubled the number of patients with no evidence of disease on imaging,” said Susan Galbraith, Executive Vice President, Oncology Haematology R&D at AstraZeneca. “This marks the first major evolution in treatment in this first-line setting in more than a decade – a setting where a strong response is crucial, as up to one third of patients may not receive second-line therapy.”
Ken Takeshita, Global Head of R&D at Daiichi Sankyo, added: “ENHERTU in combination with pertuzumab delayed disease progression for more than three years compared to around two years with current standard of care as a first-line treatment for patients with HER2-positive metastatic breast cancer. Receiving Priority Review moves us closer to offering ENHERTU to patients even earlier in the metastatic treatment pathway as a potential new first-line treatment option.”
The FDA’s action date is expected during the first quarter of 2026. The application is also being reviewed under the agency’s Real-Time Oncology Review program, designed to expedite access to promising cancer therapies.
The DESTINY-Breast09 trial, presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, also reported an objective response rate of 85.1 percent for ENHERTU plus pertuzumab compared with 78.6 percent for THP, including 58 complete responses versus 33 in the control arm. The safety profile of the ENHERTU combination was consistent with known data for the individual agents, with no new safety concerns identified.
HER2-positive metastatic breast cancer is an aggressive form of the disease that affects 15 to 20 percent of patients with metastatic breast cancer, with roughly 10,000 patients in the U.S. treated in the first-line setting each year.
ENHERTU, a specifically engineered HER2-directed DXd antibody drug conjugate discovered by Daiichi Sankyo, is already approved in more than 85 countries for second-line treatment of HER2-positive breast cancer based on the Phase III DESTINY-Breast03 trial.
