Enhertu (trastuzumab deruxtecan) in combination with pertuzumab has been approved in China for the first-line treatment of adult patients with unresectable or metastatic HER2 positive breast cancer. Enhertu is a specifically engineered HER2 directed DXd Antibody Drug Conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed and commercialised by Daiichi Sankyo and AstraZeneca.

The approval of Enhertu by China’s National Medical Products Administration (NMPA) is based on results from the DESTINY-Breast09 phase 3 trial presented at the 2025 American Society of Clinical Oncology Annual Meeting and subsequently published in The New England Journal of Medicine.

In DESTINY-Breast09, Enhertu in combination with pertuzumab reduced the risk of disease progression or death by 44 percent versus taxane, trastuzumab and pertuzumab (THP) (hazard ratio: 0.56; 95 percent Confidence Interval [CI]: 0.44-0.71; p<0.00001) in patients with HER2 positive metastatic breast cancer who had not received prior chemotherapy or HER2 targeted therapy or had received neoadjuvant or adjuvant HER2 targeted therapy more than 6 months before the diagnosis of advanced or metastatic disease. Median Progression-Free Survival (PFS) was 40.7 months (95 percent CI: 36.5-Not Estimable [NE]) with Enhertu in combination with pertuzumab compared to 26.9 months (95 percent CI: 21.8-NE) with THP as assessed by Blinded Independent Central Review (BICR). Consistent improvement in PFS was observed across prespecified subgroups. The efficacy results in the China?subgroup were consistent with the global efficacy?results.

Jiang Zefei, MD, President-Elect of the Chinese Society of Clinical Oncology and Principal Investigator in China of the DESTINY-Breast09 trial, said, “Despite advances in HER2 targeted therapies, HER2 positive metastatic breast cancer remains a challenging disease to treat, with optimising first-line therapeutic strategies and extending survival remaining the central priorities. In DESTINY-Breast09, Enhertu in combination with pertuzumab showed a median Progression-Free Survival of more than 3 years and supports the potential for this regimen to become a new standard of care in this setting. We are optimistic that this therapeutic approach will bring meaningful benefits to a broader population of patients in China.”

The safety profile of Enhertu in combination with pertuzumab in DESTINY-Breast09 was consistent with previous clinical trials with no new safety concerns identified. Grade 3 or grade 4 adverse reactions (≥1 percent) from a pooled safety analysis of 431 patients with unresectable or metastatic breast cancer treated with Enhertu (5.4 mg/kg) in combination with pertuzumab across two clinical studies included neutropenia (24.8 percent), hypokalemia (13.2 percent), anemia (10.7 percent), diarrhea (7.4 percent), fatigue (7.2 percent), thrombocytopenia (7.0 percent), increased transaminases (5.3 percent), leukopenia (5.1 percent), nausea (4.9 percent), lymphopenia (3.9 percent), decreased ejection fraction (3.2 percent), decreased weight (2.8 percent), febrile neutropenia (2.3 percent), decreased appetite (2.1 percent), vomiting (2.1 percent), upper respiratory tract infection (1.6 percent), and stomatitis (1.2 percent). Grade 5 adverse reactions occurred in 0.9 percent of patients, including Interstitial Lung Disease (ILD) (0.5 percent). Discontinuation of treatment due to an adverse reaction occurred in 15.3 percent of patients. The most frequent adverse reaction (>2 percent) associated with permanent discontinuation was ILD (6.0 percent).

Michio Hayashi, China President, Daiichi Sankyo, said, “This approval marks a major milestone for patients with HER2 positive metastatic breast cancer in China as it brings Enhertu into the first-line treatment setting, which has the potential to improve long-term outcomes for patients. In less than a year, Enhertu has been approved for 4 new indications in China, underscoring our commitment to bring this transformative medicine to patients.”

Enhertu (5.4 mg/kg) in combination with pertuzumab also is approved in India, Israel, Saudi Arabia, Singapore, South Korea, Switzerland, Taiwan, the United Arab Emirates (UAE) and the US as a first-line treatment for adult patients with unresectable or metastatic HER2 positive (IHC 3+ or ISH+) breast cancer, as determined by a locally or regionally approved test, based on the results from the DESTINY-Breast09 trial.

Mary Guan, General Manager, China Oncology Business, AstraZeneca, said, “Today’s approval brings Enhertu into the earliest treatment setting for HER2 positive metastatic breast cancer. DESTINY-Breast09 sets a new benchmark for Progression-Free Survival and offers more patients the opportunity for durable disease control earlier in the course of their disease, reinforcing the importance of continued scientific innovation to redefine treatment expectations. We are committed to working closely with partners across the healthcare ecosystem to help eligible patients in China gain access to this innovative medicine as quickly as possible.”