News|Articles|May 18, 2026

FDA Expands Enhertu into Early HER2-Positive Breast Cancer with Dual New Indications

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Key Takeaways

Neoadjuvant T-DXd→THP achieved higher pCR than ddAC-THP (67.3% vs 56.3%; p=0.003), supporting anthracycline-sparing escalation for high-risk stage 2–3 HER2-positive disease.
Safety favored the T-DXd regimen versus ddAC-THP, with fewer grade ≥3 adverse events and less hematologic toxicity, aligning with efforts to reduce chemotherapy burden without compromising efficacy.
Adjuvant T-DXd improved outcomes in residual disease post–trastuzumab-based neoadjuvant therapy, reducing invasive recurrence or death by 53% versus T-DM1 (HR 0.47; p<0.0001).
ILD/pneumonitis warrants ongoing vigilance, occurring in 9.6% with T-DXd in DESTINY-Breast05 and including two grade 5 events despite an otherwise consistent safety profile.
Earlier-stage expansion intensifies HER2 ADC competition and reinforces strategic biopharma investment in precision oncology platforms where curative intent heightens tolerance for durable benefit but demands rigorous risk mitigation.

FDA approvals for Enhertu in both neoadjuvant and adjuvant HER2-positive early breast cancer settings mark a major expansion of antibody-drug conjugates into curative-intent treatment, supported by pivotal Phase 3 DESTINY-Breast11 and DESTINY-Breast05 data.

The FDA has approved two new indications for AstraZeneca and Daiichi Sankyo’s trastuzumab deruxtecan (Enhertu), extending the HER2-directed antibody-drug conjugate (ADC) into both neoadjuvant and adjuvant treatment settings for patients with HER2-positive early breast cancer.¹ The approvals, announced May 15, 2026, were supported by findings from the Phase 3 DESTINY-Breast11 and DESTINY-Breast05 trials and further expand Enhertu’s role beyond metastatic disease.¹

The approvals reinforce the accelerating adoption of ADCs across oncology and underscore increasing competition in HER2-targeted breast cancer.

The decision positions Enhertu among a growing class of ADCs moving earlier into treatment paradigms where the therapeutic goal is cure rather than disease control. Approximately one in five breast cancers are HER2-positive, and recurrence risk remains significant despite existing standard-of-care regimens.¹

DESTINY-Breast11 showed improved pathologic complete response

The neoadjuvant approval covers adults with HER2-positive Stage 2 or 3 breast cancer receiving Enhertu followed by taxane, trastuzumab, and pertuzumab (THP).¹ In DESTINY-Breast11, investigators compared the regimen against dose-dense doxorubicin/cyclophosphamide followed by THP (ddAC-THP).²

The trial demonstrated a pathologic complete response rate of 67.3% with Enhertu followed by THP versus 56.3% with ddAC-THP, representing an 11.2% improvement (p=0.003).^1,2 Investigators also reported lower rates of Grade 3 or higher adverse events and reduced hematologic toxicities compared with the anthracycline-containing control regimen.¹

DESTINY-Breast11 enrolled 927 patients globally and evaluated whether Enhertu-based treatment could improve early response outcomes in high-risk HER2-positive disease.³ The study reflects broader industry efforts to reduce chemotherapy burden while improving efficacy in earlier-stage cancers.

Adjuvant data demonstrated reduced recurrence risk

The second FDA approval applies to patients with residual invasive disease after prior trastuzumab-based neoadjuvant therapy.¹ In DESTINY-Breast05, Enhertu reduced the risk of invasive disease recurrence or death by 53% compared with trastuzumab emtansine (T-DM1) (HR 0.47; 95% CI 0.34–0.66; p<0.0001).¹

At three years, 92.4% of patients treated with Enhertu remained alive and free of invasive disease compared with 83.7% of patients receiving T-DM1.¹Results from the study were published in The New England Journal of Medicine earlier this year.⁴

Safety findings remained consistent with the established Enhertu profile, although interstitial lung disease/pneumonitis continued to be monitored closely. Drug-related ILD/pneumonitis occurred in 9.6% of patients receiving Enhertu in DESTINY-Breast05, including two Grade 5 events.¹

ADC competition continues intensifying in oncology

The approvals reinforce the accelerating adoption of ADCs across oncology and underscore increasing competition in HER2-targeted breast cancer. Enhertu is already approved in more than 95 countries across multiple HER2-expressing tumor types, including metastatic breast cancer, gastric cancer, and HER2-mutated non-small cell lung cancer.¹

The expanded early-stage breast cancer indications also strengthen AstraZeneca’s broader oncology strategy around precision therapeutics and ADC platforms, an area drawing sustained investment across large biopharma and biotech companies.

References

Enhertu approved in the US for two new indications for patients with HER2-positive early breast cancer. (2026, May 15). AstraZeneca. Retrieved May 18, 2026. https://www.astrazeneca.com/media-centre/press-releases/2026/enhertu-approved-in-two-her2-early-bc-settings.html
Harbeck, N., Modi, S., Pusztai, L., et al. (2026 Feb). Neoadjuvant trastuzumab deruxtecan alone or followed by paclitaxel, trastuzumab, and pertuzumab for high-risk HER2-positive early breast cancer (DESTINY-Breast11): A randomized, open-label, multicenter, phase III trial. Annals of Oncology. https://pubmed.ncbi.nlm.nih.gov/41130363/
Trastuzumab Deruxtecan (T-DXd) Alone or in Sequence With THP, Versus Standard Treatment (ddAC-THP), in HER2-positive Early Breast Cancer. (2026). ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT05113251?term=DESTINY-Breast11&viewType=Card&rank=1
Loibl, S., et al. (2025 Dec 10). Trastuzumab deruxtecan in residual HER2-positive early breast cancer. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa2514661

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