Enhertu Breast Cancer Treatment Gains FDA Approval in Neoadjuvant and Adjuvant Settings

Enhertu breast cancer treatment has secured FDA approval for neoadjuvant use in adults with HER2-positive Stage II or III disease before surgery, followed by taxane plus trastuzumab and pertuzumab, and for adjuvant therapy in patients with residual invasive disease after prior trastuzumab-based regimens. These decisions rest on the DESTINY-Breast11 and DESTINY-Breast05 Phase III trials, which showed higher pathologic complete response rates and a reduced risk of invasive disease recurrence or death. The approvals mark the first time the therapy is positioned across both pre- and post-surgical settings, extending its established role in metastatic disease into earlier, curative-intent stages.

Strong Efficacy Data Support Clinical Impact

In the neoadjuvant DESTINY-Breast11 trial, Enhertu breast cancer treatment followed by taxane, trastuzumab, and pertuzumab achieved a pathologic complete response rate of 67.3 percent versus 56.3 percent with dose-dense doxorubicin and cyclophosphamide, for an absolute improvement of 11.2 percent. In the adjuvant DESTINY-Breast05 trial, the agent reduced the risk of invasive disease recurrence or death by 53 percent versus trastuzumab emtansine, with three-year invasive disease-free survival rates of 92.4 percent versus 83.7 percent. These results, presented at the 2025 ESMO Congress, underpin the Category 1 NCCN recommendation for high-risk residual disease.

Trial Designs and Tolerability Back Regulatory Decisions

Both studies used randomized, open-label, multicenter Phase III designs with well-defined endpoints. Safety data revealed no new signals, and rates of interstitial lung disease or pneumonitis remained comparable to or only modestly higher than controls. The filings benefited from concurrent review under Project Orbis, enabling aligned international assessment.

HEOR and Market-Access Considerations

Movement of the therapy into neoadjuvant and adjuvant settings creates fresh considerations for health economics, outcomes research, and payer strategies. Gains in pathologic complete response and invasive disease-free survival may lower downstream costs tied to metastatic progression. Milestone payments of $155 million from AstraZeneca to Daiichi Sankyo underscore the commercial weight of these indications.