By Fineline Cube 
AstraZeneca plc (NYSE: AZN) and Daiichi Sankyo (TYO: 4568) announced that a new indication for Enhertu (trastuzumab deruxtecan for injection) has been approved in China — for use in combination with pertuzumab in the first-line treatment of adult patients with unresectable or metastatic HER2-positive breast cancer, extending the blockbuster ADC into the earliest treatment setting in the world’s second-largest pharmaceutical market.
Regulatory Milestone
| Item | Detail |
|---|---|
| Companies | AstraZeneca plc (NYSE: AZN) × Daiichi Sankyo (TYO: 4568) |
| Product | Enhertu (trastuzumab deruxtecan for injection) |
| Approval | New indication approval in China |
| Indication | First-line treatment of adult patients with unresectable or metastatic HER2-positive breast cancer, in combination with pertuzumab |
| Approval Date | 12 Aug 2026 |
| Supporting Trial | Phase III DESTINY-Breast09 |
Drug Profile – Trastuzumab Deruxtecan
- Modality: HER2-directed antibody-drug conjugate (ADC)
- Platform: Designed using Daiichi Sankyo’s proprietary DXd ADC technology
- Development: Designed by Daiichi Sankyo; jointly developed and commercialized by Daiichi Sankyo and AstraZeneca
- Strategic Position: One of oncology’s highest-selling ADCs, now advancing from later-line use into first-line HER2-positive breast cancer
Clinical Evidence – DESTINY-Breast09 (Phase III)
| Endpoint | T-DXd + Pertuzumab | THP (Taxane + Trastuzumab + Pertuzumab) | Relative Benefit |
|---|---|---|---|
| Risk of Progression or Death | – | – | 44% risk reduction |
| Hazard Ratio (HR) | 0.56 (95% CI: 0.44–0.71) | Reference | p < 0.00001 |
| Median PFS (BICR) | 40.7 months (95% CI: 36.5–NE) | 26.9 months (95% CI: 21.8–NE) | +13.8 months |
| Subgroup Consistency | Consistent PFS improvements across prespecified subgroups; China subgroup consistent with global population | – | Broad applicability |
- Study Population: Patients with HER2-positive metastatic breast cancer who had received no prior chemotherapy or HER2-targeted therapy for advanced disease, or who had completed neoadjuvant/adjuvant HER2-targeted therapy more than six months before diagnosis of advanced or metastatic disease
- Assessment: Progression-free survival assessed by blinded independent central review (BICR)
Market Impact & Outlook
- Standard of Care Shift: A 44% reduction in progression-or-death risk against the entrenched THP regimen establishes a compelling new first-line option and pressures the long-standing taxane backbone standard.
- China Commercial Significance: China carries one of the world’s largest HER2-positive breast cancer populations; first-line approval materially expands Enhertu’s addressable market in the region.
- ADC Franchise Momentum: The approval extends the Enhertu franchise into earlier lines of therapy, a pattern driving the ADC’s global uptake and supporting the Daiichi Sankyo–AstraZeneca alliance as one of oncology’s most commercially consequential partnerships.
- Next Steps: Pricing, reimbursement access, and launch timelines in China were not disclosed.
Forward‑Looking Statements
This brief contains forward-looking statements regarding the commercialization and clinical potential of Enhertu in China. Actual results may differ due to risks including reimbursement outcomes, market adoption, safety monitoring, and competitive dynamics in HER2-targeted oncology.-Fineline Info & Tech