TOKYO — September 18, 2026
Daiichi Sankyo and AstraZeneca announced that the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has issued a positive opinion recommending approval of Enhertu® (trastuzumab deruxtecan) as adjuvant treatment for adults with resected HER2-positive breast cancer who have residual invasive disease following neoadjuvant taxane-based and HER2-targeted treatment. The recommendation is based on results from the Phase 3 DESTINY-Breast05 trial, in which Enhertu reduced the risk of invasive disease recurrence or death by 53% compared with T-DM1 (HR=0.47; p<0.0001). The recommendation will now be reviewed by the European Commission, which has authority to grant marketing authorization in the EU.
DESTINY-Breast05 Demonstrates Durable Disease Control
DESTINY-Breast05 showed significant improvements in invasive disease-free survival (IDFS) and disease-free survival (DFS) for patients receiving Enhertu compared with T-DM1. At three years, the IDFS rate was 92.4% with Enhertu versus 83.7% with T-DM1, while the three-year DFS rate was 92.3% and 83.5%, respectively. The trial enrolled 1,635 patients with HER2-positive early breast cancer and residual invasive disease in the breast or axillary lymph nodes following neoadjuvant therapy and at high risk of recurrence. The primary endpoint was investigator-assessed IDFS, with DFS serving as the key secondary endpoint.
Enhertu Adds an ADC Option in the Adjuvant Setting
Enhertu is a HER2-directed antibody-drug conjugate (ADC) developed using Daiichi Sankyo’s proprietary DXd ADC technology, combining a HER2 monoclonal antibody with a topoisomerase I inhibitor payload. The CHMP recommendation could expand its use into an earlier-stage treatment setting in the EU, where T-DM1 is currently the standard adjuvant therapy for patients with residual invasive HER2-positive disease after neoadjuvant treatment. Enhertu has already been approved for this adjuvant indication in Brazil, Canada, India and the U.S. based on DESTINY-Breast05 results, while its broader development program continues across multiple HER2-expressing cancers.
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Enhertu Safety Profile Remains Consistent With Known Risks
The safety profile in DESTINY-Breast05 was consistent with the established safety profile of Enhertu, with no new safety concerns identified. The most common treatment-related adverse events included nausea (71.3%), constipation (32.0%), decreased neutrophil count (31.6%) and vomiting (31.0%). Interstitial lung disease or pneumonitis occurred in 9.6% of Enhertu-treated patients as determined by an independent adjudication committee, with most events being Grade 1 or Grade 2. Two Grade 5 ILD or pneumonitis events (0.2%) were reported. If approved by the European Commission, the CHMP recommendation would further expand the role of Enhertu in curative-intent HER2-positive breast cancer.
Source :Daiichi Sankyo press release
