Company: AZN
Filing Date: 2025-12-22
Form Type: 6-K
Source: 0001654954-25-014166
Chunk: 2

Company: ASTRAZENECA PLC
Filing Date: 2025-12-22
Form: 6-K
Chunk 2
---
 occur as a result of HER2 gene amplification and is often associated with aggressive disease and poor prognosis in breast cancer. 2 Approximately one in five cases of breast cancer are considered HER2 positive. 3

For patients with HER2-positive early breast cancer, achieving pathologic complete response (pCR) with neoadjuvant treatment is the earliest indicator of improved long-term survival. 4 However, approximately half of patients who receive neoadjuvant treatment do not experience pCR, putting them at increased risk of disease recurrence. 5-9

Despite receiving additional treatment with T-DM1 for residual disease in the post-neoadjuvant setting, approximately 20% of patients still experience invasive disease or death, with no reduction in the risk of central nervous system recurrence. 10-11 Once patients are diagnosed with metastatic disease, the five-year survival rate drops from nearly 90% to approximately 30%. 1 2

Post-neoadjuvant therapy represents a key opportunity to minimise the risk of recurrence and prevent progression to metastatic disease for patients with residual disease. New treatment options are needed in the early breast cancer setting to help reduce the likelihood of disease progression and improve long-term outcomes for more patients. 13,14**

#### DESTINY-Breast05
DESTINY-Breast05 is a global, multicentre, randomised, open-label, Phase III trial evaluating the efficacy and safety of Enhertu (5.4 mg/kg) versus trastuzumab emtansine (T-DM1) in patients with HER2-positive early breast cancer with residual invasive disease in breast or axillary lymph nodes following neoadjuvant therapy and a high risk of recurrence. High risk of recurrence was defined as presentation with inoperable cancer (prior to neoadjuvant therapy) or pathologically positive axillary lymph nodes following neoadjuvant therapy.

The primary endpoint of DESTINY-Breast05 is investigator-assessed invasive disease-free survival (IDFS). IDFS is defined as the time from randomisation until first invasive local, axillary or distant recurrence or death from any cause. The key secondary endpoint is investigator-assessed disease-free survival. Other secondary endpoints include overall survival, distant recurrence-free interval, brain metastases-free interval and safety.

DESTINY-Breast05 enrolled 1,635 patients in Asia, Europe, North America, Oceania and South America. For more information about the trial, visit ClinicalTrials.gov .

#### Enhertu