AstraZeneca has announced encouraging high-level results from its DESTINY-Breast11 phase 3 clinical trial, which evaluated Enhertu (trastuzumab deruxtecan) in patients with high-risk, locally advanced HER2-positive early-stage breast cancer.
The trial, conducted in collaboration with Daiichi Sankyo, marks a significant step forward in the treatment landscape for this aggressive form of breast cancer.
Key Findings from DESTINY-Breast11
- Statistically and Clinically Meaningful Improvement: The study demonstrated that Enhertu, followed by a regimen of paclitaxel, trastuzumab, and pertuzumab (THP), led to a statistically significant and clinically meaningful improvement in the pathologic complete response (pCR) rate compared to the current standard of care. Achieving pCR-meaning no invasive cancer detected in the breast tissue and lymph nodes after treatment-is a key indicator linked to improved long-term outcomes for patients.
- Safety Profile: Enhertu followed by THP also showed an improved safety profile relative to the standard ddAC-THP regimen. The safety characteristics were consistent with known profiles of the individual medicines, and no new safety concerns were identified. Rates of interstitial lung disease, a potential side effect, were similar between the two treatment arms, as confirmed by an independent committee.
- Secondary Endpoints: While the trial’s secondary endpoint of event-free survival (EFS) was not mature at the time of analysis, early data suggest a favorable trend for Enhertu followed by THP over conventional treatments. The trial will continue to monitor longer-term outcomes.
Implications for Breast Cancer Treatment
Enhertu is already established as a key treatment for metastatic HER2-positive breast cancer. The DESTINY-Breast11 results highlight its potential to move into earlier stages of the disease, where curative outcomes are possible.
Around one in three patients with early-stage breast cancer are considered high risk, facing a greater chance of recurrence and poorer prognosis. Current neoadjuvant (pre-surgery) treatments often include anthracyclines, which can be difficult for patients to tolerate and may have long-term side effects.
The new data suggest Enhertu could offer a more effective and potentially safer alternative for these patients.
Data from the DESTINY-Breast11 trial will be presented at an upcoming medical meeting and shared with regulatory authorities, potentially paving the way for broader approval of Enhertu in early-stage HER2-positive breast cancer.
Market Reaction
Despite the positive clinical news, AstraZeneca shares were down nearly 2% in London trading on Wednesday, reflecting broader market trends and recent sector volatility.
However, the trial results reinforce AstraZeneca’s leadership in oncology and its commitment to advancing innovative therapies for patients with unmet needs.