AstraZeneca

AstraZeneca and Daiichi Sankyo’s supplemental Biologics License Application (sBLA) for Enhertu (trastuzumab deruxtecan) has been accepted and granted Priority Review in the US for the treatment of adult patients with HER2-positive breast cancer who have residual invasive disease after neoadjuvant HER2-targeted treatment.

The Food and Drug Administration (FDA) grants Priority Review to applications for medicines that, if approved, would offer significant improvements over available treatment options by demonstrating safety or efficacy improvements, preventing serious conditions or enhancing patient compliance. The Prescription Drug User Fee Act date, the FDA action date for its regulatory decision, is anticipated during the third quarter of 2026.

Enhertu was recently granted Breakthrough Therapy Designation (BTD) by the FDA in this setting. BTD accelerates the development and regulatory review of potential new medicines intended to treat a serious condition and address a significant unmet medical need.

The sBLA also is being reviewed under Project Orbis, which provides a framework for concurrent submission and review of oncology medicines among participating international partners.

Around one in five breast cancers are considered HER2-positive, a subtype that is often associated with aggressive disease and poor prognosis.^1-3 Currently, approximately half of patients with HER2-positive early breast cancer have residual disease following neoadjuvant treatment (before surgery), putting them at an increased risk of disease recurrence.^4-9 Despite receiving additional treatment in the post-neoadjuvant setting with current standards of care, some patients still experience tumour progression to metastatic disease, where the five-year survival rate drops from nearly 90% to approximately 30%.^10,11

Susan Galbraith, Executive Vice President, Oncology Haematology R&D, AstraZeneca, said: “While there has been significant progress in treating HER2-positive early breast cancer, managing patients at a higher risk of recurrence remains challenging. With this Priority Review, we move closer to bringing Enhertu to the post-neoadjuvant setting, offering more patients the opportunity for sustained long-term outcomes and a potential path to cure.”

Ken Takeshita, Global Head, R&D, Daiichi Sankyo, said: “For patients with residual invasive disease after neoadjuvant therapy, identifying additional treatments following surgery is critical to help further reduce the risk of recurrence and help prevent progression to metastatic disease. This Priority Review reinforces the potential of Enhertu to become a new standard of care for HER2-positive early breast cancer based on the results of DESTINY-Breast05.”

The sBLA is based on data from the DESTINY-Breast05 Phase III trial presented at the European Society for Medical Oncology (ESMO) 2025 Congress and subsequently published in The New England Journal of Medicine.¹

In the trial, Enhertu significantly reduced the risk of invasive disease recurrence or death (invasive disease-free survival [IDFS]) by 53% compared with trastuzumab emtansine (T-DM1; based on a hazard ratio [HR] of 0.47; 95% confidence interval [CI] 0.34-0.66; p<0.0001) as a post-neoadjuvant treatment for patients with HER2-positive breast cancer. Enhertu demonstrated a three-year IDFS rate of 92.4% compared with 83.7% with T-DM1. IDFS findings were consistent across all prespecified subgroups.

Enhertu also significantly reduced the risk of disease recurrence or death (disease-free survival [DFS]), a key secondary endpoint, by 53% versus T-DM1 (HR 0.47; 95% CI 0.34-0.66; p<0.0001). Further, Enhertu lowered the risk of distant disease recurrence (distant recurrence-free interval) by 51% and the risk of brain metastases (brain metastasis-free interval) by 36% compared with T-DM1 (HR 0.64; 95% CI 0.35-1.17).

The safety profile of Enhertu observed in DESTINY-Breast05 was consistent with its known profile with no new safety concerns identified.

Regulatory submissions for Enhertu based upon DESTINY-Breast05 are also under review in the EU and Japan. In addition, an sBLA for Enhertu followed by paclitaxel, trastuzumab and pertuzumab (THP) currently is under review in the US for the neoadjuvant treatment of patients with HER2-positive early breast cancer based on results from the DESTINY-Breast11 trial.

Enhertu is already approved in more than 90 countries as a treatment for patients with HER2-positive metastatic breast cancer.

Enhertu is a specifically engineered HER2-directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo. 

Notes

Post-neoadjuvant treatment for HER2-positive early breast cancer
Breast cancer is the second most common cancer and one of the leading causes of cancer-related deaths worldwide.¹²More than two million breast cancer cases were diagnosed in 2022, with more than 665,000 deaths globally.¹² In the US, more than 320,000 cases of breast cancer are diagnosed annually with more than 42,000 deaths.¹³

HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of many types of tumours including breast cancer.¹⁴ HER2 protein overexpression may occur as a result of HER2 gene amplification and is often associated with aggressive disease and poor prognosis in breast cancer.¹⁴ Approximately one in five cases of breast cancer are considered HER2-positive.^2-3

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

Despite receiving additional treatment for residual disease in the post-neoadjuvant setting, some patients still experience invasive disease or death, and current treatment options have shown limited impact on central nervous system recurrence.¹¹ In the US, around 16,000 patients with HER2-positive early breast cancer receive treatment in the post-neoadjuvant setting (after surgery) each year.¹⁵

DESTINY-Breast05
DESTINY-Breast05 is a global, multicentre, randomised, open-label, Phase III trial evaluating the efficacy and safety of Enhertu (5.4mg/kg) versus 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 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
Enhertu is a HER2-directed ADC. Designed using Daiichi Sankyo’s proprietary DXd ADC Technology, Enhertu is the lead ADC in the oncology portfolio of Daiichi Sankyo and the most advanced programme in AstraZeneca’s ADC scientific platform. Enhertu consists of a HER2 monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers.

Enhertu (5.4mg/kg) in combination with pertuzumab is approved in the US as a 1st-line treatment for adult patients with unresectable or metastatic HER2-positive (IHC 3+ or ISH+) breast cancer, as determined by an FDA-approved test based on the results from the DESTINY-Breast09 trial.

Enhertu (5.4mg/kg) is approved in more than 90 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic HER2-positive (IHC 3+ or ISH+) breast cancer who have received a prior anti-HER2-based regimen, either in the metastatic setting or in the neoadjuvant or adjuvant setting, and have developed disease recurrence during or within six months of completing therapy based on the results from the DESTINY-Breast03 trial.

Enhertu (5.4mg/kg) is approved in more than 90 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer who have received a prior systemic therapy in the metastatic setting or developed disease recurrence during or within six months of completing adjuvant chemotherapy based on the results from the DESTINY-Breast04 trial.

Enhertu (5.4mg/kg) is approved in more than 60 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic hormone receptor (HR)-positive, HER2-low (IHC 1+ or IHC 2+/ ISH-) or HER2-ultralow (IHC 0 with membrane staining) breast cancer, as determined by a locally or regionally approved test, that have progressed on one or more endocrine therapies in the metastatic setting based on the results from the DESTINY-Breast06 trial.

Enhertu (5.4mg/kg) is approved in more than 70 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic non-small cell lung cancer (NSCLC) whose tumours have activating HER2 (ERBB2) mutations, as detected by a locally or regionally approved test, and who have received a prior systemic therapy based on the results from the DESTINY-Lung02 and/or DESTINY-Lung05 trials. Continued approval in China and the US for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

Enhertu (6.4mg/kg) is approved in more than 80 countries/regions worldwide for the treatment of adult patients with locally advanced or metastatic HER2-positive (IHC 3+ or IHC 2+/ISH+) gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received a prior trastuzumab-based regimen based on the results from the DESTINY-Gastric01, DESTINY-Gastric02 and/or DESTINY-Gastric06 trials. Continued approval in China for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

Enhertu (5.4mg/kg) is approved in more than 10 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic HER2-positive (IHC 3+) solid tumours who have received prior systemic treatment and have no satisfactory alternative treatment options based on efficacy results from the DESTINY-PanTumor02, DESTINY-Lung01 and DESTINY-CRC02 trials. Continued approval for this indication in the US may be contingent upon verification and description of clinical benefit in a confirmatory trial.

Enhertu clinical development programme
A comprehensive global clinical development programme is underway evaluating the efficacy and safety of Enhertu as a monotherapy, in combination or sequentially with other cancer medicines across multiple HER2-targetable cancers.

Daiichi Sankyo collaboration
AstraZeneca and Daiichi Sankyo entered into a global collaboration to jointly develop and commercialise Enhertu in March 2019 and Datroway (datopotamab deruxtecan) in July 2020, except in Japan where Daiichi Sankyo maintains exclusive rights for each ADC. Daiichi Sankyo is responsible for the manufacturing and supply of Enhertu and Datroway.

AstraZeneca in breast cancer
Driven by a growing understanding of breast cancer biology, AstraZeneca is challenging, and redefining, the current clinical paradigm for how breast cancer is classified and treated to deliver even more effective treatments to patients in need – with the bold ambition to one day eliminate breast cancer as a cause of death.

AstraZeneca has a comprehensive portfolio of approved and promising compounds in development that leveragedifferent mechanisms of action to address the biologically diverse breast cancer tumour environment.

With Enhertu, AstraZeneca and Daiichi Sankyo are aiming to improve outcomes in previously treated HER2-positive, HER2-low and HER2-ultralow metastatic breast cancer, and are exploring its potential in earlier lines of treatment and in new breast cancer settings.

In HR-positive breast cancer, AstraZeneca continues to improve outcomes with foundational medicines Faslodex (fulvestrant) and Zoladex (goserelin) and aims to reshape the HR-positive space with first-in-class AKT inhibitor, Truqap (capivasertib), the TROP-2-directed ADC, Datroway, and next-generation oral SERD and potential new medicine camizestrant.

PARP inhibitor Lynparza (olaparib) is a targeted treatment option that has been studied in early and metastatic breast cancer patients with an inherited BRCA mutation. AstraZeneca with MSD (Merck & Co., Inc. in the US and Canada) continue to research Lynparza in these settings. AstraZeneca is also exploring the potential of saruparib, a potent and selective inhibitor of PARP1, in combination with camizestrant in BRCA-mutated, HR-positive, HER2-negative advanced breast cancer.

To bring much-needed treatment options to patients with triple-negative breast cancer, an aggressive form of breast cancer, AstraZeneca is collaborating with Daiichi Sankyo to evaluate the potential of Datroway alone and in combination with immunotherapy Imfinzi (durvalumab). 

AstraZeneca in oncology
AstraZeneca is leading a revolution in oncology with the ambition to provide cures for cancer in every form, following the science to understand cancer and all its complexities to discover, develop and deliver life-changing medicines to patients.

The Company's focus is on some of the most challenging cancers. It is through persistent innovation that AstraZeneca has built one of the most diverse portfolios and pipelines in the industry, with the potential to catalyse changes in the practice of medicine and transform the patient experience.

AstraZeneca has the vision to redefine cancer care and, one day, eliminate cancer as a cause of death.

AstraZeneca
AstraZeneca (LSE/STO/NYSE: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca’s innovative medicines are sold in more than 125 countries and used by millions of patients worldwide. Please visit astrazeneca.com and follow the Company on Social Media @AstraZeneca.

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References

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