Highest reported pathologic complete response rate seen in a Phase III registrational trial for HER2-positive early breast cancer with favorable safety profile vs. standard treatment
DESTINY-Breast11 presented in ESMO Presidential Symposium alongside DESTINY-Breast05 reinforce potential for AstraZeneca and Daiichi Sankyo’s ENHERTU to become a foundational treatment in curative-intent early breast cancer setting
WILMINGTON, Del.–(BUSINESS WIRE)–Positive results from the DESTINY-Breast11 Phase III trial showed ENHERTU® (fam-trastuzumab deruxtecan-nxki) followed by paclitaxel, trastuzumab and pertuzumab (THP) in the neoadjuvant setting (before surgery) demonstrated a statistically significant and clinically meaningful improvement in the pathologic complete response (pCR) rate. The trial compared ENHERTU followed by THP with dose-dense doxorubicin and cyclophosphamide followed by THP (ddAC-THP) in patients with high-risk, locally advanced HER2-positive early-stage breast cancer. Pathologic complete response is defined as no evidence of invasive cancer cells in the removed breast tissue and lymph nodes following treatment.
In DESTINY-Breast11, ENHERTU followed by THP resulted in a pCR rate of 67.3% compared with 56.3% for ddAC-THP, representing a pCR rate improvement of 11.2%. Improvement in pCR rates was observed across both hormone receptor (HR)-positive and HR-negative subgroups (HR-positive: 61.4% versus 52.3%; HR-negative: 83.1% versus 67.1%). Additionally, after surgery, 81.3% of patients who received neoadjuvant treatment in the ENHERTU followed by THP arm had no or minimal residual invasive cancer (residual cancer burden [RCB] 0+I) detected in the resected breast or lymph node tissue compared to 69.1% of patients in the comparator arm.
The secondary endpoint of event-free survival (EFS) was not mature at the time of this analysis (4.5% maturity at data cutoff); however, an early analysis showed a trend favoring ENHERTU followed by THP versus ddAC-THP (hazard ratio 0.56; 95% CI 0.26-1.17).
Nadia Harbeck, MD, PhD, Director of Breast Center, Cancer Department of OB&GYN and CCC Munich, LMU University Hospital, Germany and principal investigator for the trial, said: “For patients with early breast cancer who are at high risk of disease recurrence, using the most effective treatment option at the earliest opportunity is critical to prevent recurrence, optimise safety and improve the potential for cure. In the DESTINY-Breast11 trial, more than two thirds of patients had a pathologic complete response with trastuzumab deruxtecan followed by THP, suggesting a potential new standard of care in the neoadjuvant setting for patients with high-risk, HER2-positive early breast cancer.”
Susan Galbraith, Executive Vice President, Oncology Haematology R&D, AstraZeneca, said: “The goal of treatment in the early breast cancer setting is to provide patients with the best possible chance for cure whilst optimising the tolerability of the treatment regimen. The impressive pathologic response rates and favourable safety profile seen with Enhertu followed by THP in DESTINY-Breast11 have the potential to transform treatment in the neoadjuvant setting and underscore the importance of bringing Enhertu into earlier stages of HER2-positive disease.”
Ken Takeshita, Global Head, R&D, Daiichi Sankyo, said: “While achieving a pathologic complete response in HER2-positive early-stage breast cancer is critical for reducing disease recurrence and improving long-term prognosis, approximately half of patients still show evidence of residual disease following surgery with currently available neoadjuvant treatment options. The results from DESTINY-Breast11 show that treatment with Enhertu followed by THP prior to surgery resulted in no evidence of residual invasive disease in two thirds of patients, illustrating the first treatment regimen in more than a decade to significantly improve outcomes in the earliest treatment setting for HER2-positive breast cancer.”
Summary of Results: DESTINY-Breast11i,ii
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Efficacy Measure |
ENHERTU (5.4 mg/kg; 4 cycles) followed by THP (4 cycles) (n=321) |
ddAC (4 cycles) followed by THP (4 cycles) |
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pCR |
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pCR rate, %iii |
67.3 |
56.3 |
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ΔpCR,% (95% CI)iii,iv |
11.2 (4.0-18.3) |
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p=0.003 |
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HR-positive subgroup pCR rate, %iii |
61.4 |
52.3 |
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ΔpCR, % (95% CI) |
9.1 (0.2-17.9) |
|
|
HR-negative subgroup pCR rate, % iii |
83.1 |
67.1 |
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ΔpCR, % (95% CI) |
16.1 (3.0-28.8) |
|
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RCB (0+I)v |
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RCB (0+I rate), % |
81.3 |
69.1 |
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ΔRCB, % |
12.2 |
|
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RCB-I rate, % |
68.8 |
57.5 |
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RCB-0 rate, % |
12.5 |
11.6 |
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HR-positive subgroup RCB (0+I) rate, % |
78.0 |
64.7 |
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ΔRCB, % (95% CI) |
13.3 |
|
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HR-positive RCB-I rate, % |
63.1 |
52.8 |
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HR-positive RCB-0 rate, % |
14.8 |
11.9 |
|
HR-negative subgroup RCB (0+I) rate, %v |
90.4 |
81.2 |
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ΔpCR, % (95% CI) |
9.2 |
|
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HR-negative RCB-I rate, % |
84.3 |
70.6 |
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HR-negative RCB-0 rate, % |
6.0 |
10.6 |
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EFSvi |
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2-year EFS, % Hazard ratio (95% CI) |
96.9 |
93.1 |
|
0.56 (0.26, 1.17) |
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THP, paclitaxel, trastuzumab and pertuzumab; ddAC, dose-dense doxorubicin and cyclophosphamide; pCR, pathologic complete response; HR, hormone receptor; CI, confidence interval; RCB (0+I), residual cancer burden; EFS, event-free survival |
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i Data cut-off March 12, 2025; median duration of follow up was 24.2 months with ENHERTU followed by THP and 23.6 months with ddAC-THP |
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The safety profile of ENHERTU followed by THP in DESTINY-Breast11 was consistent with the known profiles of each individual therapy with no new safety concerns identified.
ENHERTU followed by THP showed a favorable safety profile compared with ddAC-THP with reduced rates of Grade 3 or higher adverse events (AEs) (37.5% versus 55.8%), serious AEs (10.6% versus 20.2%), treatment interruptions (37.8% versus 54.5%) and left ventricular dysfunction (1.3% versus 6.1%).
Rates of interstitial lung disease (ILD) were low and similar between arms with ILD events occurring in 4.4% of patients in the ENHERTU followed by THP arm compared with 5.1% in the ddAC-THP arm. The majority of ILD events were low Grade (Grade 1 and 2). There was one Grade 3/4 event in the ENHERTU followed by THP arm and five Grade 3/4 events in the ddAC-THP arm. There was one Grade 5 ILD event in each arm as determined by an independent adjudication committee.
DESTINY-Breast11 results (abstract #291O) will be presented today during Presidential Symposium I, alongside the results from the DESTINY-Breast05 Phase III trial (abstract #LBA1) at the European Society for Medical Oncology (ESMO) 2025 Congress in Berlin, Germany. The DESTINY-Breast11 results will also be published in the Annals of Oncology in parallel with ESMO.
A supplemental Biologics License Application for ENHERTU followed by THP based on the results from DESTINY-Breast11 is currently under review by the US Food and Drug Administration (FDA).
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.
IMPORTANT SAFETY INFORMATION FOR ENHERTU® (fam-trastuzumab deruxtecan-nxki)
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 <10%, continue treatment with ENHERTU and repeat LVEF assessment within 3 weeks. When LVEF is 40-45% and absolute decrease from baseline is 10-20%, interrupt ENHERTU and repeat LVEF assessment within 3 weeks. If LVEF has not recovered to within 10% from baseline, permanently discontinue ENHERTU. If LVEF recovers to within 10% from baseline, resume treatment with ENHERTU at the same dose. When LVEF is <40% or absolute decrease from baseline is >20%, interrupt ENHERTU and repeat LVEF assessment within 3 weeks. If LVEF of <40% or absolute decrease from baseline 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. The median duration of treatment was 14 months (range: 0.7 to 30) for patients who received ENHERTU.
Serious adverse reactions occurred in 19% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were vomiting, ILD, pneumonia, pyrexia, and urinary tract infection. Fatalities due to adverse reactions occurred in 0.8% of patients including COVID-19 and sudden death (1 patient each).
ENHERTU was permanently discontinued in 14% of patients, of which ILD/pneumonitis accounted for 8%. Dose interruptions due to adverse reactions occurred in 44% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose interruption were neutropenia, leukopenia, anemia, thrombocytopenia, pneumonia, nausea, fatigue, and ILD/pneumonitis. Dose reductions occurred in 21% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were nausea, neutropenia, and fatigue.
The most common (≥20%) adverse reactions, including laboratory abnormalities, were nausea (76%), decreased white blood cell count (74%), decreased neutrophil count (70%), increased aspartate aminotransferase (67%), decreased hemoglobin (64%), decreased lymphocyte count (55%), increased alanine aminotransferase (53%), decreased platelet count (52%), fatigue (49%), vomiting (49%), increased blood alkaline phosphatase (49%), alopecia (37%), decreased blood potassium (35%), constipation (34%), musculoskeletal pain (31%), diarrhea (29%), decreased appetite (29%), headache (22%), respiratory infection (22%), abdominal pain (21%), increased blood bilirubin (20%), and stomatitis (20%).
HER2-Low and HER2-Ultralow Metastatic Breast Cancer
DESTINY-Breast06
The safety of ENHERTU was evaluated in 434 patients with unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) or HER2-ultralow (IHC 0 with membrane staining) breast cancer who received ENHERTU 5.4 mg/kg intravenously once every 3 weeks in DESTINY-Breast06. The median duration of treatment was 11 months (range: 0.4 to 39.6) for patients who received ENHERTU.
Serious adverse reactions occurred in 20% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were ILD/pneumonitis, COVID-19, febrile neutropenia, and hypokalemia. Fatalities due to adverse reactions occurred in 2.8% of patients including ILD (0.7%); sepsis (0.5%); and COVID-19 pneumonia, bacterial meningoencephalitis, neutropenic sepsis, peritonitis, cerebrovascular accident, general physical health deterioration (0.2% each).
ENHERTU was permanently discontinued in 14% of patients. The most frequent adverse reaction (>2%) associated with permanent discontinuation was ILD/pneumonitis. Dose interruptions due to adverse reactions occurred in 48% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose interruption were COVID-19, decreased neutrophil count, anemia, pyrexia, pneumonia, decreased white blood cell count, and ILD. Dose reductions occurred in 25% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were nausea, fatigue, decreased platelet count, and decreased neutrophil count.
The most common (≥20%) adverse reactions, including laboratory abnormalities, were decreased white blood cell count (86%), decreased neutrophil count (75%), nausea (70%), decreased hemoglobin (69%), decreased lymphocyte count (66%), fatigue (53%), decreased platelet count (48%), alopecia (48%), increased alanine aminotransferase (44%), increased blood alkaline phosphatase (43%), increased aspartate aminotransferase (41%), decreased blood potassium (35%), diarrhea (34%), vomiting (34%), constipation (32%), decreased appetite (26%), COVID-19 (26%), and musculoskeletal pain (24%).
DESTINY-Breast04
The safety of ENHERTU was evaluated in 371 patients with unresectable or metastatic HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer who received ENHERTU 5.4 mg/kg intravenously once every 3 weeks in DESTINY-Breast04. The median duration of treatment was 8 months (range: 0.2 to 33) for patients who received ENHERTU.
Serious adverse reactions occurred in 28% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were ILD/pneumonitis, pneumonia, dyspnea, musculoskeletal pain, sepsis, anemia, febrile neutropenia, hypercalcemia, nausea, pyrexia, and vomiting. Fatalities due to adverse reactions occurred in 4% of patients including ILD/pneumonitis (3 patients); sepsis (2 patients); and ischemic colitis, disseminated intravascular coagulation, dyspnea, febrile neutropenia, general physical health deterioration, pleural effusion, and respiratory failure (1 patient each).
ENHERTU was permanently discontinued in 16% of patients, of which ILD/pneumonitis accounted for 8%. Dose interruptions due to adverse reactions occurred in 39% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose interruption were neutropenia, fatigue, anemia, leukopenia, COVID-19, ILD/pneumonitis, increased transaminases, and hyperbilirubinemia.
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