ENHERTU® (fam-trastuzumab deruxtecan-nxki) reduced the risk of disease progression or death by 72% vs. trastuzumab emtansine (T-DM1) in patients with HER2-positive metastatic breast cancer

Rhea-AI Summary

Results from the DESTINY-Breast03 Phase III trial indicate that ENHERTU significantly outperformed T-DM1 in treating previously treated HER2-positive breast cancer, offering a 72% reduction in progression risk (HR 0.28). With a median progression-free survival (PFS) not yet reached for ENHERTU versus 6.8 months for T-DM1 and a confirmed objective response rate (ORR) of 79.7%, the drug showcases promising efficacy. Safety data revealed manageable adverse events with no Grade 4 or 5 interstitial lung disease cases. These findings support ENHERTU's potential as a new standard of care.

Positive

• ENHERTU demonstrated superior progression-free survival (PFS) with a 72% reduction in disease progression risk compared to T-DM1 (HR 0.28).
• Median PFS for ENHERTU has not been reached versus T-DM1's 6.8 months, indicating a potentially longer duration of efficacy.
• ENHERTU achieved a high overall response rate of 79.7%, with a substantial number of complete responses (16.1%) compared to T-DM1 (8.7%).
• A significant percentage of patients (94.1%) treated with ENHERTU were alive at one year, compared to 85.9% for T-DM1.
• Safety profile was encouraging, with no Grade 4 or 5 interstitial lung disease events in the study.

Negative

• The overall survival (OS) benefit seen with ENHERTU is not yet statistically significant, indicating that further data is needed.
• There were notable treatment-related adverse events, including 10.5% of patients experiencing interstitial lung disease.

Ground-breaking Phase III head-to-head DESTINY-Breast03 results featured at ESMO Presidential Symposium support ENHERTU as the potential new standard of care in previously treated patients

DESTINY-Breast01 Phase II trial data also presented at ESMO showed impressive median overall survival of 29.1 months in HER2-positive patients following two or more HER2-based regimens

WILMINGTON, Del.--(BUSINESS WIRE)-- Detailed positive results from the head-to-head DESTINY-Breast03 Phase III trial showed that ENHERTU^® (fam-trastuzumab deruxtecan-nxki), the AstraZeneca and Daiichi Sankyo Company, Limited (hereafter, Daiichi Sankyo) HER2-directed antibody drug conjugate (ADC), demonstrated superior progression-free survival (PFS) versus trastuzumab emtansine (T-DM1), a HER2-directed ADC currently approved to treat patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane. Results were presented today in a Presidential Symposium at the European Society for Medical Oncology (ESMO) Congress 2021.

At a prespecified interim analysis of DESTINY-Breast03, ENHERTU provided a 72% reduction in the risk of disease progression or death compared to T-DM1, (hazard ratio [HR] 0.28; 95% confidence interval [CI] 0.22-0.37; p=7.8X10^-22). After 15.5 and 13.9 months of follow-up in the ENHERTU and T-DM1 arms respectively, the median PFS for patients treated with ENHERTU was not reached (95% CI 18.5-NE) compared to 6.8 months for T-DM1 (95% CI 5.6-8.2) as assessed by blinded independent central review (BICR). In the key secondary endpoint of PFS assessed by investigators, patients treated with ENHERTU experienced a three-fold improvement in PFS of 25.1 months versus 7.2 months T-DM1 (HR 0.26; 95% CI 0.20-0.35; p=6.5x10^-24). A consistent PFS benefit was observed across key subgroups of patients treated with ENHERTU, including those with a history of stable brain metastases.

There was a strong trend towards improved overall survival (OS) with ENHERTU (HR 0.56; 95% CI 0.36-0.86; nominal p=0.007172), however this analysis is not yet mature and is not statistically significant. Nearly all patients treated with ENHERTU were alive at one year (94.1%) compared to 85.9% of patients treated with T-DM1.

Confirmed objective response rate (ORR) more than doubled in the ENHERTU arm versus the T-DM1 arm (79.7% vs. 34.2%). Forty-two (16.1%) complete responses (CR), and 166 (63.6%) partial responses (PR) were observed in patients treated with ENHERTU compared to 23 (8.7%) CRs and 67 (25.5%) PRs in patients treated with T-DM1.

Javier Cortés, MD, PhD, Head, International Breast Cancer Center (IBCC), Barcelona, said: “Patients with previously treated HER2-positive metastatic breast cancer will typically experience disease progression in less than a year with available HER2-directed treatments. The high and consistent benefit seen across efficacy endpoints and key subgroups of patients receiving ENHERTU in DESTINY-Breast03 is remarkable and support the potential of ENHERTU to become the new standard of care for those who have previously been treated for HER2-positive metastatic breast cancer.”

Susan Galbraith, Executive Vice President, Oncology R&D, said: “Today’s results are ground-breaking. ENHERTU tripled progression-free survival as assessed by investigators, and provided a disease control rate exceeding 95% compared 77% for T-DM1 in DESTINY-Breast03. In addition, the safety profile was encouraging with no Grade 4 or 5 interstitial lung disease events in this trial. These unprecedented data represent a potential paradigm shift in the treatment of HER2-positive metastatic breast cancer, and illustrate the potential for ENHERTU to transform more patient lives in this earlier disease settings.”

Ken Takeshita, Global Head, R&D, Daiichi Sankyo, said: “The early survival data, which evaluated ENHERTU against another HER2-directed ADC, showed that nearly all patients treated with ENHERTU were alive after a year and is a positive indication of the potential of this medicine to transform the treatment of HER2-positive metastatic breast cancer. These landmark data will form the basis of our discussions with global health authorities to potentially bring ENHERTU to patients with previously treated HER2-positive metastatic breast cancer as a more effective treatment option as soon as possible.”

Summary of results: DESTINY-Breast03

Efficacy Measure	Enhertu (5.4 mg/kg) Total Evaluable (n=261)i	T-DM1 (3.6 mg/kg) Total Evaluable (n=263)
PFSii (95% CI)
Hazard ratio (95% CI)	0.28 (0.22-0.37)
p-value	p=7.8x10-22
Median PFS (months) (95% CI)ii	NR (18.5-NE)	6.8 months (5.6-8.2)
Landmark 12-month PFS (%) (95% CI)ii	75.8% (69.8-80.7)	34.1% (27.7-40.5)
PFS as assessed by investigators (95% CI)
Hazard ratio (95% CI)	0.26 (0.20-0.35)
p-value	p=6.5x10-24
Median PFS (months) (95% CI)	25.1 months (22.1-NE)	7.2 months (6.8-8.3)
OS
Hazard ratio (95% CI)	0.56 (0.36-0.86)
p-value	p=0.007172iii
Landmark 12-month OS (%) (95% CI)	94.1% (90.3-96.4)	85.9% (80.9-89.7)
Median OS (months) (95% CI)	NE	NE
Confirmed ORR (%) (95% CI)ii,iv	79.7% (74.3-84.4)	34.2% (28.5-40.3)
Complete response (%)	16.1% (42)	8.7% (23)
Partial response (%)	63.6% (166)	25.5% (67)
Stable disease (%)	16.9% (44)	42.6% (112)
Progressive disease (%) (95% CI)	1.1% (3)	17.5% (46)
DCRv	96.6% (252)	76.8% (202)

ⁱ Dose used in the study being presented
ⁱⁱ As assessed by blind independent central review
ⁱⁱⁱ Not statistically significant
^iv ORR is (CR + PR)
^v DCR is (CR+PR+SD)

The safety profile of the most common adverse events with ENHERTU in DESTINY-Breast03 was consistent with previous clinical trials with no new safety concerns identified. The most common Grade 3 or higher treatment-emergent adverse events in the ENHERTU arm were neutropenia (19.1%), thrombocytopenia (7.0%), leukopenia (6.6%) and nausea (6.6%). There were 27 cases (10.5%) of treatment-related interstitial lung disease (ILD) or pneumonitis reported, as determined by an independent adjudication committee. The majority (9.7%) were low Grade (Grade 1 or Grade 2), with two Grade 3 (0.8%) events. No Grade 4 or Grade 5 ILD or pneumonitis events occurred.

DESTINY-Breast01 Updated Results

Updated results from the pivotal DESTINY-Breast01 Phase II trial were also presented at ESMO and showed that ENHERTU (5.4 mg/kg) continued to demonstrate impressive efficacy and durable responses in patients with HER2-positive metastatic breast cancer following two or more prior HER2-based regimens. With a median duration follow-up of 26.5 months, a continued increase in response was seen in patients treated with ENHERTU with an updated ORR of 62.0%, including one additional CR (7.1%). A median duration of response (DoR) of 18.2 months was also observed. The median PFS was 19.4 months. In an exploratory analysis of OS with a median follow-up of 31.1 months, evaluated at a greater maturity (52%), the updated median OS was 29.1 months.

The overall safety and tolerability profile seen with ENHERTU in DESTINY-Breast01 continues to be consistent with what has been previously observed. There has been one new case of treatment-related Grade 1 ILD or pneumonitis determined by an independent adjudication committee as of data cut-off of March 26, 2021.

ENHERTU is approved for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting in the US, Japan, the EU and several other countries based on the results from the DESTINY-Breast01 trial.

ENHERTU is being further assessed in a comprehensive clinical development program evaluating efficacy and safety across multiple HER2-targetable cancers, including breast, gastric, lung and colorectal cancers.

Several presentations featured during the ESMO Congress 2021 will showcase the strength and depth of ENHERTU data across multiple tumor types, including gastric, lung and breast cancers, reinforcing the transformational potential of this medicine in the treatment of HER2-targetable cancers.

Important Safety Information

Indications

ENHERTU is a HER2-directed antibody and topoisomerase inhibitor conjugate indicated for the treatment of adult patients with:

• Unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting.
  
  This indication is approved under accelerated approval based on tumor 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 gastric or gastroesophageal junction adenocarcinoma who have received a prior trastuzumab-based regimen.

WARNING: INTERSTITIAL LUNG DISEASE and EMBRYO-FETAL TOXICITY   Interstitial lung disease (ILD) and pneumonitis, including fatal cases, have been reported with ENHERTU. Monitor for and promptly investigate signs and symptoms including cough, dyspnea, fever, and other new or worsening respiratory symptoms. Permanently discontinue ENHERTU in all patients with Grade 2 or higher ILD/pneumonitis. Advise patients of the risk and to immediately report symptoms.   Exposure to ENHERTU during pregnancy can cause embryo-fetal harm. Advise patients of these risks and the need for effective contraception.

Contraindications

None.

Warnings and Precautions

Severe, life-threatening, or fatal interstitial lung disease (ILD), including pneumonitis, can occur in patients treated with ENHERTU. 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 one 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.

Metastatic Breast Cancer

In clinical studies, of the 234 patients with unresectable or metastatic HER2-positive breast cancer treated with ENHERTU 5.4 mg/kg, ILD occurred in 9% of patients. Fatal outcomes due to ILD and/or pneumonitis occurred in 2.6% of patients treated with ENHERTU. Median time to first onset was 4.1 months (range: 1.2 to 8.3).

Locally Advanced or Metastatic Gastric Cancer

In DESTINY-Gastric01, of the 125 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 21.0).

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. Reduce dose by one level. For febrile neutropenia (ANC <1.0 x 10⁹/L and temperature >38.3ºC or a sustained temperature of ≥38ºC for more than 1 hour), interrupt ENHERTU until resolved. Reduce dose by one level.

Metastatic Breast Cancer

In clinical studies, of the 234 patients with unresectable or metastatic HER2-positive breast cancer who received ENHERTU 5.4mg/kg, a decrease in neutrophil count was reported in 62% of patients. Sixteen percent had Grade 3 or 4 decrease in neutrophil count. Median time to first onset of decreased neutrophil count was 23 days (range: 6 to 547). Febrile neutropenia was reported in 1.7% of patients.

Locally Advanced or Metastatic Gastric Cancer

In DESTINY-Gastric01, of the 125 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. In the 234 patients with unresectable or metastatic HER2-positive breast cancer who received ENHERTU, two cases (0.9%) of asymptomatic LVEF decrease were reported. In DESTINY-Gastric01, of the 125 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. 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.

Assess LVEF prior to initiation of ENHERTU and at regular intervals during treatment as clinically indicated. 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.

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 at least 7 months following the last dose of ENHERTU. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with ENHERTU and for at least 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. Reduce dose by one level.

Adverse Reactions

Metastatic Breast Cancer

The safety of ENHERTU was evaluated in a pooled analysis of 234 patients with unresectable or metastatic HER2-positive breast cancer who received at least one dose of ENHERTU 5.4 mg/kg in DESTINY-Breast01 and Study DS8201-A-J101. ENHERTU was administered by intravenous infusion once every three weeks. The median duration of treatment was 7 months (range: 0.7 to 31).

Serious adverse reactions occurred in 20% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were interstitial lung disease, pneumonia, vomiting, nausea, cellulitis, hypokalemia, and intestinal obstruction. Fatalities due to adverse reactions occurred in 4.3% of patients including interstitial lung disease (2.6%), and the following events occurred in one patient each (0.4%): acute hepatic failure/acute kidney injury, general physical health deterioration, pneumonia, and hemorrhagic shock.

ENHERTU was permanently discontinued in 9% of patients, of which ILD accounted for 6%. Dose interruptions due to adverse reactions occurred in 33% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose interruption were neutropenia, anemia, thrombocytopenia, leukopenia, upper respiratory tract infection, fatigue, nausea, and ILD. Dose reductions occurred in 18% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were fatigue, nausea, and neutropenia.

The most common (≥20%) adverse reactions, including laboratory abnormalities, were nausea (79%), white blood cell count decreased (70%), hemoglobin decreased (70%), neutrophil count decreased (62%), fatigue (59%), vomiting (47%), alopecia (46%), aspartate aminotransferase increased (41%), alanine aminotransferase increased (38%), platelet count decreased (37%), constipation (35%), decreased appetite (32%), anemia (31%), diarrhea (29%), hypokalemia (26%), and cough (20%).

Locally Advanced or Metastatic Gastric Cancer

The safety of ENHERTU was evaluated in 187 patients with locally advanced or metastatic HER2‑positive gastric or GEJ adenocarcinoma in DESTINY‑Gastric01. Patients intravenously received at least one dose of either ENHERTU (N=125) 6.4 mg/kg once every three weeks or either irinotecan (N=55) 150 mg/m² biweekly or paclitaxel (N=7) 80 mg/m² weekly for 3 weeks. The median duration of treatment was 4.6 months (range: 0.7 to 22.3) in the ENHERTU group and 2.8 months (range: 0.5 to 13.1) in the irinotecan/paclitaxel group.

Serious adverse reactions occurred in 44% of patients receiving ENHERTU 6.4 mg/kg. Serious adverse reactions in >2% of patients who received ENHERTU were decreased appetite, ILD, anemia, dehydration, pneumonia, cholestatic jaundice, pyrexia, and tumor hemorrhage. Fatalities due to adverse reactions occurred in 2.4% of patients: disseminated intravascular coagulation, large intestine perforation, and pneumonia occurred in one patient each (0.8%).

ENHERTU was permanently discontinued in 15% of patients, of which ILD accounted for 6%. Dose interruptions due to adverse reactions occurred in 62% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose interruption were neutropenia, anemia, decreased appetite, leukopenia, fatigue, thrombocytopenia, ILD, pneumonia, lymphopenia, upper respiratory tract infection, diarrhea, and hypokalemia. Dose reductions occurred in 32% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were neutropenia, decreased appetite, fatigue, nausea, and febrile neutropenia.

The most common (≥20%) adverse reactions, including laboratory abnormalities, were hemoglobin decreased (75%), white blood cell count decreased (74%), neutrophil count decreased (72%), lymphocyte count decreased (70%), platelet count decreased (68%), nausea (63%), decreased appetite (60%), anemia (58%), aspartate aminotransferase increased (58%), fatigue (55%), blood alkaline phosphatase increased (54%), alanine aminotransferase increased (47%), diarrhea (32%), hypokalemia (30%), vomiting (26%), constipation (24%), blood bilirubin increased (24%), pyrexia (24%), and alopecia (22%).

Use in Specific Populations

• Pregnancy: ENHERTU can cause fetal harm when administered to a pregnant woman. Advise patients of the potential risks to a fetus. There are clinical considerations if ENHERTU is used in pregnant women, or if a patient becomes pregnant within 7 months following the last dose of ENHERTU.
• Lactation: There are no data regarding the presence of ENHERTU in human milk, the effects on the breastfed child, or the effects on milk production. Because of the potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatment with ENHERTU and for 7 months after the last dose.
• Females and Males of Reproductive Potential: Pregnancy testing: Verify pregnancy status of females of reproductive potential prior to initiation of ENHERTU. Contraception: Females: ENHERTU can cause fetal harm when administered to a pregnant woman. Advise females of reproductive potential to use effective contraception during treatment with ENHERTU and for at least 7 months following the last dose. Males: Advise male patients with female partners of reproductive potential to use effective contraception during treatment with ENHERTU and for at least 4 months following the last dose. Infertility: ENHERTU may impair male reproductive function and fertility.
• Pediatric Use: Safety and effectiveness of ENHERTU have not been established in pediatric patients.
• Geriatric Use: Of the 234 patients with HER2-positive breast cancer treated with ENHERTU 5.4 mg/kg, 26% were ≥65 years and 5% were ≥75 years. No overall differences in efficacy were observed between patients ≥65 years of age compared to younger patients. There was a higher incidence of Grade 3-4 adverse reactions observed in patients aged ≥65 years (53%) as compared to younger patients (42%). Of the 125 patients with locally advanced or metastatic HER2‑positive gastric or GEJ adenocarcinoma treated with ENHERTU 6.4 mg/kg in DESTINY-Gastric01, 56% were ≥65 years and 14% were ≥75 years. No overall differences in efficacy or safety were observed between patients ≥65 years of age compared to younger patients.
• Hepatic Impairment: In patients with moderate hepatic impairment, due to potentially increased exposure, closely monitor for increased toxicities related to the topoisomerase inhibitor.

To report SUSPECTED ADVERSE REACTIONS, contact Daiichi Sankyo, Inc. at 1-877-437-7763 or FDA at 1-800-FDA-1088 or fda.gov/medwatch.

Please see accompanying full Prescribing Information, including Boxed WARNINGS, and Medication Guide.

HER2-positive breast cancer

Breast cancer remains the most common cancer and is one of the leading causes of cancer-related deaths in women worldwide.¹ More than two million patients with breast cancer were diagnosed in 2020, resulting in nearly 685,000 deaths globally.¹ Approximately one in five cases of breast cancer are considered HER2-positive.²

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.³ HER2 protein overexpression may occur as a result of HER2 gene amplification and is often associated with aggressive disease and a poor prognosis in breast cancer.⁴

Despite initial treatment with trastuzumab and a taxane, people with HER2-positive metastatic breast cancer will often experience disease progression.⁵ More effective options are needed to further delay progression and extend survival.^5-7

DESTINY-Breast03

DESTINY-Breast03 is a global head-to-head, randomised, open-label, registrational Phase III trial evaluating the safety and efficacy of ENHERTU (5.4mg/kg) versus T-DM1 in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane. The primary efficacy endpoint of DESTINY-Breast03 is PFS based on blinded independent central review. Secondary efficacy endpoints include OS, objective response rate, duration of response, clinical benefit rate, PFS based on investigator assessment and safety.

DESTINY-Breast03 enrolled approximately 500 patients at multiple sites in Asia, Europe, North America, Oceania and South America. For more information about the trial, visit ClinicalTrials.gov.

DESTINY-Breast01

DESTINY-Breast01 is a registrational Phase II, single-arm, open-label, global, multi-center, two-part trial evaluating the safety and efficacy of ENHERTU in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with T-DM1. The primary endpoint of the trial is ORR, as determined by ICR. Secondary objectives include DoR, disease control rate, clinical benefit rate, PFS and OS.

DESTINY-Breast01 enrolled 253 patients at multiple sites in Asia, Europe and North America. For more information about the trial, visit ClinicalTrials.gov.

ENHERTU

ENHERTU (fam-trastuzumab deruxtecan-nxki) 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 topoisomerase I inhibitor payload, an exatecan derivative, via a stable tetrapeptide-based cleavable linker.

ENHERTU (5.4mg/kg) is approved in Canada, the EU, Israel, Japan, the UK and the US for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting based on the results from the DESTINY-Breast01 trial.

ENHERTU (6.4mg/kg) is also approved in Israel, Japan and the US for the treatment of adult patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma who have received a prior trastuzumab-based regimen based on the results from the DESTINY-Gastric01 trial.

ENHERTU development program

A comprehensive development program is underway globally, evaluating the efficacy and safety of ENHERTU monotherapy across multiple HER2-targetable cancers, including breast, gastric, lung and colorectal cancers. Trials in combination with other anticancer treatments, such as immunotherapy, are also underway.

ENHERTU was highlighted in the Clinical Cancer Advances 2021 report as one of two significant advancements in the “ASCO Clinical Advance of the Year: Molecular Profiling Driving Progress in GI Cancers,” based on data from both the DESTINY-CRC01 and DESTINY-Gastric01 trials, as well as one of the targeted therapy advances of the year in non-small cell lung cancer (NSCLC), based on the interim results of the HER2-mutated cohort of the DESTINY-Lung01 trial.

In May 2020, ENHERTU also received Breakthrough Therapy Designation for the treatment of patients with metastatic NSCLC whose tumors have a HER2-mutation and with disease progression on or after platinum-based therapy.

Daiichi Sankyo collaboration

Daiichi Sankyo and AstraZeneca entered into a global collaboration to jointly develop and commercialize ENHERTU (a HER2-directed ADC) in March 2019, and datopotamab deruxtecan (DS-1062; a TROP2-directed ADC) in July 2020, except in Japan where Daiichi Sankyo maintains exclusive rights. Daiichi Sankyo is responsible for manufacturing and supply of ENHERTU and datopotamab deruxtecan.

AstraZeneca in breast cancer

Driven by a growing understanding of breast cancer biology, AstraZeneca is starting to challenge, and redefine, 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 leverage different mechanisms of action to address the biologically diverse breast cancer tumor environment. AstraZeneca aims to continue to transform outcomes for HR-positive breast cancer with foundational medicines fulvestrant and goserelin and the next-generation oral SERD and potential new medicine AZD9833.

PARP inhibitor, olaparib is a targeted treatment option for metastatic breast cancer patients with an inherited BRCA mutation. AstraZeneca with MSD (Merck & Co., Inc. in the US and Canada) continue to research olaparib in metastatic breast cancer patients with an inherited BRCA mutation and are exploring new opportunities to treat these patients earlier in their disease.

Building on the first approval of ENHERTU, a HER2-directed ADC, in previously treated HER2-positive metastatic breast cancer, AstraZeneca and Daiichi Sankyo are exploring its potential in earlier lines of treatment and in new breast cancer settings. To bring much needed treatment options to patients with triple-negative breast cancer, an aggressive form of breast cancer, AstraZeneca is testing immunotherapy durvalumab in combination with other oncology medicines, including olaparib and ENHERTU, investigating the potential of AKT kinase inhibitor, capivasertib, in combination with chemotherapy, and collaborating with Daiichi Sankyo to explore the potential of TROP2-directed ADC, datopotamab deruxtecan.

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.

About AstraZeneca

AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialization of prescription medicines in Oncology and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries, and its innovative medicines are used by millions of patients worldwide. For more information, please visit www.astrazeneca-us.com and follow us on Twitter @AstraZenecaUS.

References

1. Sung H, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021; 10.3322/caac.21660.
2. Ahn S, et al. HER2 status in breast cancer: changes in guidelines and complicating factors for interpretation. J Pathol Transl Med. 2020; 54(1): 34-44.
3. Iqbal N, et al. Human Epidermal Growth Factor Receptor 2 (HER2) in Cancers: Overexpression and Therapeutic Implications. Mol Biol Int. 2014;852748.
4. Pillai R, et al. HER2 mutations in lung adenocarcinomas: A report from the Lung Cancer Mutation Consortium. Cancer. 2017;1;123(21):4099-4105.
5. Barok M, et al. Trastuzumab emtansine: mechanism of action and drug resistance. Breast Cancer Res. 2014; 16(2):209.
6. Mounsey, L et al. Changing Natural History of HER2-Positive Breast Cancer Metastatic to the Brain in the Era of New Targeted Therapies. Clin Breast Cancer. 2018; 18(1):29-37.
7. Martinez-S Sáez O, et al. Current and Future Management of HER2-Positive Metastatic Breast Cancer. JCO Oncol Pract. 2021. 10.1200/OP.21.00172.

US-57299 Last Updated 9/21

View source version on businesswire.com: https://www.businesswire.com/news/home/20210918005024/en/

Media Inquiries

Holly Campbell +1 302 885 2677

Brendan McEvoy +1 302 885 2677

Source: AstraZeneca

FAQ

What are the results of the DESTINY-Breast03 trial for ENHERTU and T-DM1?

The DESTINY-Breast03 trial showed ENHERTU significantly outperformed T-DM1, offering a 72% reduction in progression risk and superior median PFS.

How does ENHERTU's efficacy compare to T-DM1 in HER2-positive breast cancer treatment?

ENHERTU displayed a median PFS not yet reached compared to T-DM1's 6.8 months, along with an overall response rate of 79.7%.

What percentage of patients treated with ENHERTU were alive at one year?

94.1% of patients treated with ENHERTU were alive at one year, compared to 85.9% for T-DM1.

What safety concerns are associated with ENHERTU treatment?

ENHERTU showed manageable safety concerns, with no Grade 4 or 5 interstitial lung disease cases reported in the trial.

Is there any significance in the overall survival rates for ENHERTU?

The overall survival benefit for ENHERTU is not yet statistically significant, indicating the need for further analysis.

What is the hazard ratio for disease progression in the DESTINY-Breast03 trial?

The hazard ratio for disease progression for ENHERTU compared to T-DM1 was reported as 0.28.