- Based on results from DESTINY-Breast11, the first phase 3 trial to demonstrate benefit of Daiichi Sankyo and AstraZeneca’s ENHERTU in early-stage breast cancer
- If approved, ENHERTU followed by THP could represent a new treatment approach prior to surgery in this setting
TOKYO & BASKING RIDGE, N.J.–(BUSINESS WIRE)–Daiichi Sankyo (TSE: 4568) and AstraZeneca’s (LSE/STO/Nasdaq: AZN) supplemental Biologics License Application (sBLA) for ENHERTU® (fam-trastuzumab deruxtecan-nxki) followed by paclitaxel, trastuzumab and pertuzumab (THP) has been accepted for review in the U.S. for the neoadjuvant treatment of adult patients with HER2 positive (IHC 3+ or ISH+) stage 2 or stage 3 breast cancer.
ENHERTU is a specifically engineered HER2 directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed and commercialized by Daiichi Sankyo and AstraZeneca.
The acceptance is based on results from the DESTINY-Breast11 phase 3 trial, which showed that ENHERTU followed by THP demonstrated a statistically significant and clinically meaningful improvement in pathologic compete response (pCR) rate along with an improved safety profile compared to dose-dense doxorubicin and cyclophosphamide followed by THP [ddAC-THP]) when used prior to surgery for patients with high-risk, locally advanced HER2 positive early-stage breast cancer. Data from the trial also showed an early positive trend in event-free survival (EFS) favoring ENHERTU followed by THP compared to ddAC-THP. The Prescription Drug User Fee Act (PDUFA) date, the FDA target action date for their regulatory decision, is May 18, 2026.
Approximately one in three patients with early-stage breast cancer are considered high-risk, meaning they are more likely to experience disease recurrence and have a poor prognosis.1,2 Achieving pCR in early-stage HER2 positive breast cancer, defined as no evidence of invasive cancer cells in the removed breast tissue and lymph nodes following treatment, is associated with improved long-term outcomes.3,4 Currently, nearly half of patients who receive neoadjuvant treatment do not achieve pCR, reinforcing the unmet medical need for new treatment options.2,5 The current standard of care in this neoadjuvant setting varies across regions but generally consists of combination chemotherapy regimens.
“Achieving a pathologic complete response prior to surgery in HER2 positive early-stage breast cancer is critical to reducing the risk of disease recurrence and improving the potential for cure,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo. “If approved, ENHERTU could change how patients with high-risk HER2 positive early-stage breast cancer are treated and we look forward to working closely with the FDA to bring this innovative treatment regimen to patients in this setting.”
“The clinically meaningful improvement in pathologic complete response and favorable safety profile seen with DESTINY-Breast11 highlight the opportunity for ENHERTU followed by THP to become an important new approach for patients with HER2 positive early breast cancer,” said Susan Galbraith, MBBChir, PhD, Executive Vice President, Oncology Hematology R&D, AstraZeneca. “ENHERTU is already established in the metastatic setting and now we have the potential to expand its use into earlier stages of disease where cure is possible.”
In DESTINY-Breast11, ENHERTU followed by THP showed an improved safety profile compared to ddAC-THP. The safety profiles of ENHERTU and THP were consistent with the known profiles of each individual medicine with no new safety concerns identified. Rates of interstitial lung disease were similar across the ENHERTU followed by THP and the ddAC-THP arms as determined by an independent adjudication committee.
Following a recommendation by the Independent Data Monitoring Committee, patient enrollment in a third arm of DESTINY-Breast11 evaluating ENHERTU alone was closed based on a previous efficacy assessment of the study arms.
ENHERTU has demonstrated improved outcomes in six phase 3 breast cancer trials across different subtypes and stages of disease, including data from the DESTINY-Breast09 phase 3 trial, which were recently presented at the 2025 American Society of Clinical Oncology (#ASCO25) Annual Meeting and granted Priority Review in the U.S., evaluating ENHERTU in the first-line HER2 positive metastatic setting, as well as positive topline results from a planned interim analysis of the DESTINY-Breast05 phase 3 trial evaluating ENHERTU versus trastuzumab emtansine (T-DM1) in patients with HER2 positive early breast cancer with residual invasive disease in the breast or axillary lymph nodes after neoadjuvant treatment and high risk of disease recurrence. Data from DESTINY-Breast11 (Abstract #291O) and DESTINY-Breast05 (Abstract #LBA1) will be presented during Presidential Symposium I on Saturday, October 18 at the upcoming 2025 European Society for Medical Oncology (#ESMO25) Congress.
About DESTINY-Breast11
DESTINY-Breast11 is a global, multicenter, randomized, open-label, phase 3 trial evaluating the efficacy and safety of neoadjuvant ENHERTU (5.4 mg/kg) monotherapy or ENHERTU followed by THP (paclitaxel, trastuzumab and pertuzumab) versus ddAC-THP in patients with high-risk (lymph node positive [N1-3] or primary tumor stage T3-4), locally advanced or inflammatory HER2 positive early-stage breast cancer.
Patients were randomized 1:1:1 to receive either eight cycles of ENHERTU monotherapy; four cycles of ENHERTU followed by four cycles of THP; or four cycles of ddAC (dose-dense doxorubicin and cyclophosphamide) followed by four cycles of THP.
The primary endpoint of DESTINY-Breast11 is rate of pCR (absence of invasive disease in the breast and lymph nodes). Secondary endpoints include EFS, invasive disease-free survival, overall survival and safety.
DESTINY-Breast11 enrolled 927 patients across multiple sites in Asia, Europe, North America and South America. For more information about the trial, visit ClinicalTrials.gov.
About HER2 Positive Early Breast Cancer
Breast cancer is the second most common cancer and one of the leading causes of cancer-related deaths worldwide.6 More than two million breast cancer cases were diagnosed in 2022, with more than 665,000 deaths globally.6 In the U.S., more than 300,000 cases of breast cancer are diagnosed annually with more than 42,000 deaths.7
HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of many types of tumors including breast, gastric, lung and colorectal cancers.8 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.9 Approximately one in five cases of breast cancer are considered HER2 positive.10
Approximately one in three patients with early-stage breast cancer are considered high-risk, as they are more likely to experience disease recurrence and have a poor prognosis.1,2 Achieving pCR in early-stage HER2 positive breast cancer is associated with improved long-term outcomes.3,4 The current standard of care in many regions of the world in this neoadjuvant setting consists of combination chemotherapy regimens. These regimens may include anthracyclines, which can be challenging for patients to tolerate and may result in long-term cardiotoxicity. Further, nearly half of patients who receive neoadjuvant treatment do not achieve pCR, reinforcing the need for new treatment options.2,5
About ENHERTU
ENHERTU (trastuzumab deruxtecan; fam-trastuzumab deruxtecan-nxki in the U.S. only) 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 program 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 (5.4 mg/kg) is approved in more than 85 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic HER2 positive (immunohistochemistry [IHC] 3+ or in-situ hybridization (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 (5.4 mg/kg) is approved in more than 85 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 (5.4 mg/kg) is approved in more than 45 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 has progressed on one or more endocrine therapies in the metastatic setting based on the results from the DESTINY-Breast06 trial.
ENHERTU (5.4 mg/kg) is approved in more than 60 countries/regions worldwide for the treatment of adult patients with unresectable or metastatic NSCLC whose tumors 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 U.S. for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.
ENHERTU (6.4 mg/kg) is approved in more than 70 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 (5.4 mg/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 tumors 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 may be contingent upon verification and description of clinical benefit in a confirmatory trial.
About the ENHERTU Clinical Development Program
A comprehensive global clinical development program is underway evaluating the efficacy and safety of ENHERTU as a monotherapy or in combination or sequentially with other cancer medicines across multiple HER2 targetable cancers.
About the Daiichi Sankyo and AstraZeneca Collaboration
Daiichi Sankyo and AstraZeneca entered into a global collaboration to jointly develop and commercialize ENHERTU in March 2019 and DATROWAY® 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.
About the ADC Portfolio of Daiichi Sankyo
The Daiichi Sankyo ADC portfolio consists of seven ADCs in clinical development crafted from two distinct ADC technology platforms discovered in-house by Daiichi Sankyo.
The ADC platform furthest in clinical development is Daiichi Sankyo’s DXd ADC Technology where each ADC consists of a monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers. The DXd ADC portfolio currently consists of ENHERTU, a HER2 directed ADC, and DATROWAY, a TROP2 directed ADC, which are being jointly developed and commercialized globally with AstraZeneca. Patritumab deruxtecan (HER3-DXd), a HER3 directed ADC, ifinatamab deruxtecan (I-DXd), a B7-H3 directed ADC, and raludotatug deruxtecan (R-DXd), a CDH6 directed ADC, are being jointly developed and commercialized globally with Merck & Co., Inc, Rahway, NJ, USA. DS-3939, a TA-MUC1 directed ADC, is being developed by Daiichi Sankyo.
The second Daiichi Sankyo ADC platform consists of a monoclonal antibody attached to a modified pyrrolobenzodiazepine (PBD) payload. DS-9606, a CLDN6 directed PBD ADC, is the first of several planned ADCs in clinical development utilizing this platform.
Ifinatamab deruxtecan, patritumab deruxtecan, raludotatug deruxtecan, DS-3939 and DS-9606 are investigational medicines that have not been approved for any indication in any country. Safety and efficacy have not been established.
ENHERTU U.S. Important Safety Information
Indications
ENHERTU is a HER2-directed antibody and topoisomerase inhibitor conjugate indicated for the treatment of adult patients with:
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Unresectable or metastatic HER2-positive (IHC 3+ or ISH positive) 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
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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 an FDA-approved test, that has progressed on one or more endocrine therapies in the metastatic setting
– HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer, as determined by an FDA-approved test, who have received a prior chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy
-
Unresectable or metastatic non-small cell lung cancer (NSCLC) whose tumors have activating HER2 (ERBB2) mutations, as detected by an FDA-approved test, and who have received a prior systemic therapy
This indication is approved under accelerated approval based on objective response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.
- Locally advanced or metastatic HER2-positive (IHC 3+ or IHC 2+/ISH positive) gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received a prior trastuzumab-based regimen
-
Unresectable or metastatic HER2-positive (IHC 3+) solid tumors who have received prior systemic treatment and have no satisfactory alternative treatment options
This indication is approved under accelerated approval based on objective response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.
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WARNING: INTERSTITIAL LUNG DISEASE and EMBRYO-FETAL TOXICITY |
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Contraindications
None.
Warnings and Precautions
Interstitial Lung Disease / Pneumonitis
Severe, life-threatening, or fatal interstitial lung disease (ILD), including pneumonitis, can occur in patients treated with ENHERTU. A higher incidence of Grade 1 and 2 ILD/pneumonitis has been observed in patients with moderate renal impairment. Advise patients to immediately report cough, dyspnea, fever, and/or any new or worsening respiratory symptoms. Monitor patients for signs and symptoms of ILD. Promptly investigate evidence of ILD. Evaluate patients with suspected ILD by radiographic imaging. Consider consultation with a pulmonologist. For asymptomatic ILD/pneumonitis (Grade 1), interrupt ENHERTU until resolved to Grade 0, then if resolved in ≤28 days from date of onset, maintain dose. If resolved in >28 days from date of onset, reduce dose 1 level. Consider corticosteroid treatment as soon as ILD/pneumonitis is suspected (e.g., ≥0.5 mg/kg/day prednisolone or equivalent). For symptomatic ILD/pneumonitis (Grade 2 or greater), permanently discontinue ENHERTU. Promptly initiate systemic corticosteroid treatment as soon as ILD/pneumonitis is suspected (e.g., ≥1 mg/kg/day prednisolone or equivalent) and continue for at least 14 days followed by gradual taper for at least 4 weeks.
HER2-Positive, HER2-Low, and HER2-Ultralow Metastatic Breast Cancer, HER2-Mutant NSCLC, and Solid Tumors (Including IHC 3+) (5.4 mg/kg)
In patients with metastatic breast cancer, HER2-mutant NSCLC, and other solid tumors treated with ENHERTU 5.4 mg/kg, ILD occurred in 12% of patients. Median time to first onset was 5.5 months (range: 0.9 to 31.5). Fatal outcomes due to ILD and/or pneumonitis occurred in 0.9% of patients treated with ENHERTU.
HER2-Positive Locally Advanced or Metastatic Gastric Cancer (6.4 mg/kg)
In patients with locally advanced or metastatic HER2-positive gastric or GEJ adenocarcinoma treated with ENHERTU 6.4 mg/kg, ILD occurred in 10% of patients. Median time to first onset was 2.8 months (range: 1.2 to 21).
Neutropenia
Severe neutropenia, including febrile neutropenia, can occur in patients treated with ENHERTU. Monitor complete blood counts prior to initiation of ENHERTU and prior to each dose, and as clinically indicated. For Grade 3 neutropenia (Absolute Neutrophil Count [ANC] <1.0 to 0.5 x 109/L), interrupt ENHERTU until resolved to Grade 2 or less, then maintain dose. For Grade 4 neutropenia (ANC <0.5 x 109/L), interrupt ENHERTU until resolved to Grade 2 or less, then reduce dose by 1 level. For febrile neutropenia (ANC <1.0 x 109/L and temperature >38.3º C or a sustained temperature of ≥38º C for more than 1 hour), interrupt ENHERTU until resolved, then reduce dose by 1 level.
HER2-Positive, HER2-Low, and HER2-Ultralow Metastatic Breast Cancer, HER2-Mutant NSCLC, and Solid Tumors (Including IHC 3+) (5.4 mg/kg)
In patients with metastatic breast cancer, HER2-mutant NSCLC, and other solid tumors treated with ENHERTU 5.4 mg/kg, a decrease in neutrophil count was reported in 65% of patients. Nineteen percent had Grade 3 or 4 decreased neutrophil count. Median time to first onset of decreased neutrophil count was 22 days (range: 2 to 939). Febrile neutropenia was reported in 1.2% of patients.
HER2-Positive Locally Advanced or Metastatic Gastric Cancer (6.4 mg/kg)
In patients with locally advanced or metastatic HER2-positive gastric or GEJ adenocarcinoma treated with ENHERTU 6.4 mg/kg, a decrease in neutrophil count was reported in 72% of patients. Fifty-one percent had Grade 3 or 4 decreased neutrophil count. Median time to first onset of decreased neutrophil count was 16 days (range: 4 to 187). Febrile neutropenia was reported in 4.8% of patients.
Left Ventricular Dysfunction
Patients treated with ENHERTU may be at increased risk of developing left ventricular dysfunction. Left ventricular ejection fraction (LVEF) decrease has been observed with anti-HER2 therapies, including ENHERTU. Assess LVEF prior to initiation of ENHERTU and at regular intervals during treatment as clinically indicated. Manage LVEF decrease through treatment interruption. When LVEF is >45% and absolute decrease from baseline is 10-20%, continue treatment with ENHERTU. When LVEF is 40-45% and absolute decrease from baseline is 20%, interrupt ENHERTU and repeat LVEF assessment within 3 weeks. If LVEF of 20% is confirmed, permanently discontinue ENHERTU. Permanently discontinue ENHERTU in patients with symptomatic congestive heart failure. Treatment with ENHERTU has not been studied in patients with a history of clinically significant cardiac disease or LVEF <50% prior to initiation of treatment.
HER2-Positive, HER2-Low, and HER2-Ultralow Metastatic Breast Cancer, HER2-Mutant NSCLC, and Solid Tumors (Including IHC 3+) (5.4 mg/kg)
In patients with metastatic breast cancer, HER2-mutant NSCLC, and other solid tumors treated with ENHERTU 5.4 mg/kg, LVEF decrease was reported in 4.6% of patients, of which 0.6% were Grade 3 or 4.
HER2-Positive Locally Advanced or Metastatic Gastric Cancer (6.4 mg/kg)
In patients with locally advanced or metastatic HER2-positive gastric or GEJ adenocarcinoma treated with ENHERTU 6.4 mg/kg, no clinical adverse events of heart failure were reported; however, on echocardiography, 8% were found to have asymptomatic Grade 2 decrease in LVEF.
Embryo-Fetal Toxicity
ENHERTU can cause fetal harm when administered to a pregnant woman. Advise patients of the potential risks to a fetus. Verify the pregnancy status of females of reproductive potential prior to the initiation of ENHERTU. Advise females of reproductive potential to use effective contraception during treatment and for 7 months after the last dose of ENHERTU. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with ENHERTU and for 4 months after the last dose of ENHERTU.
Additional Dose Modifications
Thrombocytopenia
For Grade 3 thrombocytopenia (platelets <50 to 25 x 109/L) interrupt ENHERTU until resolved to Grade 1 or less, then maintain dose. For Grade 4 thrombocytopenia (platelets <25 x 109/L) interrupt ENHERTU until resolved to Grade 1 or less, then reduce dose by 1 level.
Adverse Reactions
HER2-Positive, HER2-Low, and HER2-Ultralow Metastatic Breast Cancer, HER2-Mutant NSCLC, and Solid Tumors (Including IHC 3+) (5.4 mg/kg)
The pooled safety population reflects exposure to ENHERTU 5.4 mg/kg intravenously every 3 weeks in 2233 patients in Study DS8201-A-J101 (NCT02564900), DESTINY-Breast01, DESTINY-Breast02, DESTINY-Breast03, DESTINY-Breast04, DESTINY-Breast06, DESTINY-Lung01, DESTINY-Lung02, DESTINY-CRC02, and DESTINY-PanTumor02. Among these patients, 67% were exposed for >6 months and 38% were exposed for >1 year. In this pooled safety population, the most common (≥20%) adverse reactions, including laboratory abnormalities, were decreased white blood cell count (73%), nausea (72%), decreased hemoglobin (67%), decreased neutrophil count (65%), decreased lymphocyte count (60%), fatigue (55%), decreased platelet count (48%), increased aspartate aminotransferase (46%), increased alanine aminotransferase (44%), increased blood alkaline phosphatase (39%), vomiting (38%), alopecia (37%), constipation (32%), decreased blood potassium (32%), decreased appetite (31%), diarrhea (30%), and musculoskeletal pain (24%).
HER2-Positive Metastatic Breast Cancer
DESTINY-Breast03
The safety of ENHERTU was evaluated in 257 patients with unresectable or metastatic HER2-positive breast cancer who received at least 1 dose of ENHERTU 5.4 mg/kg intravenously once every 3 weeks in DESTINY-Breast03.
Contacts
Media Contacts:
Global/US:
Jennifer Brennan
Daiichi Sankyo
[email protected]
+1 908 900 3183 (mobile)
Japan:
Daiichi Sankyo Co., Ltd.
[email protected]
Investor Relations Contact:
[email protected]
