AstraZeneca and Daiichi Sankyo Submit Priority‑Review sBLA for Enhertu as First‑Line Therapy for HER2‑Positive Breast Cancer

AstraZeneca (AZ; NASDAQ: AZN) and Daiichi Sankyo (TYO: 4568) have filed a supplemental Biologics License Application (sBLA) with the U.S. Food & Drug Administration (FDA) for Enhertu® (trastuzumab deruxtecan). The application has been granted Priority Review and seeks approval for Enhertu as a first‑line treatment for adult patients with unresectable or metastatic HER2‑positive breast cancer.

Clinical Evidence Supporting the New Indication

• DESTINY‑Breast09 Phase III data underpin the sBLA. In a head‑to‑head comparison, Enhertu plus pertuzumab reduced the risk of disease progression or death by 44 % versus the standard taxane‑based THP (trastuzumab + pertuzumab) regimen (hazard ratio 0.56; 95 % CI 0.44‑0.71; P < 0.00001).
• Median Progression‑Free Survival (PFS):
• Enhertu + pertuzumab: 40.7 months
• THP regimen: 26.9 months
• The PFS advantage was consistent across all prespecified subgroups, underscoring the robustness of the benefit.

Product and Partnership Overview

• Enhertu is a next‑generation HER2‑directed antibody‑drug conjugate (ADC) featuring a novel DXd payload engineered by Daiichi Sankyo.
• The compound was co‑developed and co‑commercialized by Daiichi Sankyo and AstraZeneca, combining global sales expertise with cutting‑edge ADC technology.

Regulatory Implications

• Priority Review signals the FDA’s recognition of Enhertu’s potential to address an unmet need in first‑line metastatic HER2‑positive breast cancer.
• If approved, Enhertu would become the first ADC specifically approved for this setting, potentially reshaping the therapeutic landscape and expanding treatment options for patients who have limited choices beyond taxane‑based regimens.-Fineline Info & Tech