ENHERTU® (fam-trastuzumab deruxtecan-nxki) showed substantial clinical activity in patients with HER2-positive metastatic breast cancer and brain metastases

Rhea-AI Summary

AstraZeneca and Daiichi Sankyo's ENHERTU demonstrated substantial clinical activity in patients with HER2-positive metastatic breast cancer and brain metastases in the DESTINY-Breast12 Phase IIIb/IV trial. Key findings include:

- 61.6% progression-free survival rate at 12 months in patients with brain metastases
- 58.9% CNS progression-free survival rate at 12 months
- 62.7% objective response rate in patients without brain metastases
- Safety profile consistent with previous trials

The results support ENHERTU's potential role in treating patients with active or stable brain metastases, addressing a significant unmet need in HER2-positive metastatic breast cancer treatment.

Positive

• 61.6% progression-free survival rate at 12 months in patients with brain metastases
• 58.9% CNS progression-free survival rate at 12 months in patients with brain metastases
• 62.7% objective response rate in patients without brain metastases
• 90.3% 12-month overall survival rate in patients with brain metastases
• Consistent efficacy results in patients with both stable and active brain metastases
• Safety profile consistent with previous trials, with no new safety concerns identified

Negative

• 12.9% of patients without brain metastases and 16.0% with brain metastases experienced interstitial lung disease or pneumonitis
• 1.2% of patients without brain metastases and 2.3% with brain metastases experienced Grade 5 (fatal) interstitial lung disease events

Insights

Oncology Doctor

The DESTINY-Breast12 trial results demonstrate significant clinical activity of ENHERTU in HER2-positive metastatic breast cancer patients with brain metastases. The 61.6% progression-free survival rate at one year for patients with brain metastases is particularly impressive, as brain metastases are notoriously difficult to treat. The 58.9% CNS progression-free survival rate further underscores ENHERTU's efficacy in controlling intracranial disease.

Notably, the drug showed similar efficacy in both stable and active brain metastases, suggesting its potential as a versatile treatment option across different stages of brain involvement. The 62.7% objective response rate in patients without brain metastases also confirms ENHERTU's broader efficacy in HER2-positive metastatic breast cancer.

While the safety profile is consistent with previous trials, the 16% incidence of interstitial lung disease in patients with brain metastases warrants careful monitoring. Overall, these results could potentially expand treatment options for a challenging patient population with alternatives.

Financial Analyst

The positive results from the DESTINY-Breast12 trial could significantly boost the market potential of ENHERTU for AstraZeneca and Daiichi Sankyo. With up to 50% of HER2-positive metastatic breast cancer patients developing brain metastases, this data addresses a critical unmet need in a substantial patient population.

The strong efficacy data, particularly in brain metastases, could lead to expanded indications and increased adoption of ENHERTU, potentially driving sales growth. The $1.2 billion in ENHERTU sales reported by AstraZeneca for 2023 could see a substantial increase if these results lead to broader use in the metastatic setting.

However, investors should note the ongoing safety concerns, particularly the risk of interstitial lung disease, which may impact the drug's risk-benefit profile. Overall, this data strengthens ENHERTU's position in the competitive HER2-positive breast cancer market, potentially enhancing long-term revenue prospects for both companies.

Medical Research Analyst

The DESTINY-Breast12 trial results represent a significant advancement in the treatment of HER2-positive metastatic breast cancer with brain metastases. The study's design, focusing on patients with no more than two prior lines of therapy in the metastatic setting, provides valuable data for earlier use of ENHERTU in this challenging patient population.

The consistent efficacy observed across stable and active brain metastases is particularly noteworthy, suggesting ENHERTU's potential to address a broad spectrum of CNS involvement. The high CNS objective response rate of 82.6% in patients without prior local CNS therapy is especially promising, indicating ENHERTU's potential as an early treatment option for brain metastases.

While the efficacy data is impressive, the safety profile, particularly the incidence of interstitial lung disease, requires careful consideration in clinical practice. These results will likely inform future treatment guidelines and spark further research into optimizing HER2-directed therapies for patients with brain metastases.

AstraZeneca and Daiichi Sankyo’s ENHERTU achieved 61.6% progression-free survival rate at one year in patients with active or stable brain metastases in DESTINY-Breast12

Largest prospective trial of ENHERTU in this patient population

WILMINGTON, Del.--(BUSINESS WIRE)-- Results from the DESTINY-Breast12 Phase IIIb/IV trial showed that ENHERTU^® (fam-trastuzumab deruxtecan-nxki) demonstrated substantial overall and intracranial clinical activity in a large cohort of patients with HER2-positive metastatic breast cancer who have brain metastases and received no more than two prior lines of therapy in the metastatic setting. Results will be presented today as a late-breaking presentation (abstract #LBA18) at the European Society for Medical Oncology (#ESMO24) and simultaneously published in Nature Medicine.

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

In patients with brain metastases at baseline, the primary endpoint of progression-free survival (PFS) by independent central review showed a 12-month PFS rate of 61.6%. Additionally, patients with brain metastases showed a central nervous system (CNS) 12-month PFS rate of 58.9%. Results were consistent in patients with stable and active brain metastases. Patients with stable brain metastases had a 12-month PFS rate of 62.9% and a 12-month CNS PFS rate of 57.8%. Patients with active brain metastases had a 12-month PFS rate of 59.6% and a 12-month CNS PFS rate of 60.1%.

In patients without brain metastases at baseline, the primary endpoint of confirmed objective response rate (ORR) by independent central review showed an ORR of 62.7% with 23 complete responses (CR) and 128 partial responses (PR).

Nancy Lin, MD, Associate Chief, Division of Breast Oncology, Dana-Farber Cancer Institute, Boston, MA, US and principal investigator for the trial, said: “Up to fifty percent of patients with HER2-positive metastatic breast cancer experience the spread of disease to the brain during the course of their illness, which significantly impacts quality of life and outcomes. These data help further characterize the clinical benefit and safety profile of ENHERTU in these patients, which will help guide treatment decisions.”

Sunil Verma, Global Head Oncology Franchise, AstraZeneca, said “The results from DESTINY-Breast12 show substantial clinical activity for patients whose disease has spread to the brain. The data as well as the results in patients without brain metastases further build confidence in the clinical profile of ENHERTU for the second-line treatment of HER2-positive metastatic breast cancer.”

Mark Rutstein, Global Head, Oncology Development, Daiichi Sankyo, said, “Treating brain metastases in patients with breast cancer is challenging as there are few effective treatment options. Building on previous studies, these results show ENHERTU can provide strong overall and intracranial clinical activity and support its potential role in treating patients with active or stable brain metastases.”

Summary of results: DESTINY-Breast12 primary analysis

Efficacy measure	Baseline brain metastases (cohort 2)			No baseline brain metastases (cohort 1)
	Overall population (n=263)	Stable brain metastasesi (n=157)	Active brain metastasesii (n=106)	Overall population (n=241)iii
12-month PFS rate (%) (95% CI)iv	61.6 (54.9-67.6)	62.9 (54.0-70.5)	59.6 (49.0-68.7)	--
12-month CNS PFS rate (%) (95% CI)v	58.9 (51.9-65.3)	57.8 (48.2-66.1)	60.1 (49.2-69.4)	--
12 month OS rate (%) (95% CI)	90.3 (85.9-93.4)	--	--	90.6 (86.0-93.8)
Confirmed ORR (%)vi, vii (95% CI)	51.7 (45.7-57.8)	49.7 (41.9-57.5)	54.7 (45.2-64.2)	62.7 (56.5-68.8)
CR % (n)	4.2 (11)	--	--	9.5 (23)
PR % (n)	47.5 (125)	--	--	53.1 (128)viii
Confirmed CNS ORR (%) (95% CI)ix	71.7 (64.2-79.3) N=138	79.2 (70.2-88.3) N=77	62.3 (50.1-74.5) N=61	--

PFS, progression-free survival; CI, confidence interval; CNS, central nervous system; OS, overall survival; ORR, objective response rate; CR, complete response; PR, partial response

i Stable brain metastases (previously treated)

ii Active brain metastases (untreated or previously treated / progressing [not requiring immediate local therapy])

iii Includes 26 patients with no measurable disease at baseline

iv Primary endpoint for baseline brain metastases (cohort 2) was median PFS with 42.2% data maturity at time of data cutoff (8 February 2024); post-hoc analysis showed median PFS of 17.3 months (95% CI 13.7-22.1)

v Patients who had systemic progression, but no CNS progression, were censored at the time of the progression assessment; the analysis did not account for systemic progression as a competing event

vi Primary endpoint for no baseline brain metastases cohort (cohort 1)

vii ORR is (CR + PR)

viii One patient with no measurable disease at baseline was assigned PR by independent central review

ix Analysis of CNS ORR was in patients with measurable CNS disease at baseline

A post-hoc analysis in patients with active brain metastases showed the CNS ORR was 82.6% (n=19/23) for patients who had not received prior local CNS therapy and 50.0% (n=19/38) in patients who had progressed following prior local CNS therapy.

The safety profile of ENHERTU in DESTINY-Breast12 was consistent with previous breast cancer clinical trials with no new safety concerns identified. The safety profile of ENHERTU in the trial was also generally consistent between patients with brain metastases and patients without brain metastases.

Interstitial lung disease (ILD) or pneumonitis occurred in 12.9% of patients in cohort without brain metastases and 16.0% in the cohort of patients with brain metastases as determined by the investigator. The majority of ILD events were low grade (Grade 1 or 2). In patients without brain metastases, there were 22 Grade 1 ILD events, six Grade 2 events, zero Grade 3 and 4 events, and three (1.2%) Grade 5 events. In patients with brain metastases, there were 26 Grade 1 ILD events, eight Grade 2 events, one Grade 3 event, one Grade 4 event and six (2.3%) Grade 5 events. Five ILD or pneumonitis events in the brain metastases cohort were reported by the investigator as co-occurring with opportunistic infection (one Grade 4 and four Grade 5).

ENHERTU is approved in more than 65 countries for the treatment of unresectable or metastatic HER2-positive breast cancer who have received a prior anti-HER2-based regimen.

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 (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

• Unresectable or metastatic 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 (IHC3+) 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.

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
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 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.

HER2-Positive or HER2-Low 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 1.0% 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 one 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 one level.

HER2-Positive or HER2-Low 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 63% of patients. Seventeen 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% 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 or HER2-Low 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 3.8% of patients, of which 0.6% were Grade 3.

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 one level.

Adverse Reactions
HER2-Positive and HER2-Low 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 1799 patients in Study DS8201-A-J101 (NCT02564900), DESTINY-Breast01, DESTINY-Breast02, DESTINY-Breast03, DESTINY-Breast04, DESTINY-Lung01, DESTINY-Lung02, DESTINY-CRC02, and DESTINY-PanTumor02. Among these patients, 65% 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 nausea (73%), decreased white blood cell count (70%), decreased hemoglobin (66%), decreased neutrophil count (63%), decreased lymphocyte count (58%), fatigue (56%), decreased platelet count (48%), increased aspartate aminotransferase (47%), increased alanine aminotransferase (43%), vomiting (40%), increased blood alkaline phosphatase (38%), alopecia (34%), constipation (33%), decreased appetite (32%), decreased blood potassium (31%), diarrhea (29%), musculoskeletal pain (24%), and abdominal pain (20%).

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 one dose of ENHERTU 5.4 mg/kg intravenously once every three weeks in DESTINY-Breast03. The median duration of treatment was 14 months (range: 0.7 to 30).

Serious adverse reactions occurred in 19% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were vomiting, interstitial lung disease, pneumonia, pyrexia, and urinary tract infection. Fatalities due to adverse reactions occurred in 0.8% of patients including COVID-19 and sudden death (one 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 Metastatic Breast Cancer
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. Dose reductions occurred in 23% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were fatigue, nausea, thrombocytopenia, and neutropenia.

The most common (≥20%) adverse reactions, including laboratory abnormalities, were nausea (76%), decreased white blood cell count (70%), decreased hemoglobin (64%), decreased neutrophil count (64%), decreased lymphocyte count (55%), fatigue (54%), decreased platelet count (44%), alopecia (40%), vomiting (40%), increased aspartate aminotransferase (38%), increased alanine aminotransferase (36%), constipation (34%), increased blood alkaline phosphatase (34%), decreased appetite (32%), musculoskeletal pain (32%), diarrhea (27%), and decreased blood potassium (25%).

HER2-Mutant Unresectable or Metastatic NSCLC (5.4 mg/kg)
DESTINY-Lung02 evaluated two dose levels (5.4 mg/kg [n=101] and 6.4 mg/kg [n=50]); however, only the results for the recommended dose of 5.4 mg/kg intravenously every 3 weeks are described below due to increased toxicity observed with the higher dose in patients with NSCLC, including ILD/pneumonitis.

The safety of ENHERTU was evaluated in 101 patients with HER2-mutant unresectable or metastatic NSCLC who received ENHERTU 5.4 mg/kg intravenously once every three weeks until disease progression or unacceptable toxicity in DESTINY‑Lung02. Nineteen percent of patients were exposed for >6 months.

Serious adverse reactions occurred in 30% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were ILD/pneumonitis, thrombocytopenia, dyspnea, nausea, pleural effusion, and increased troponin I. Fatality occurred in 1 patient with suspected ILD/pneumonitis (1%).

ENHERTU was permanently discontinued in 8% of patients. Adverse reactions which resulted in permanent discontinuation of ENHERTU were ILD/pneumonitis, diarrhea, decreased blood potassium, hypomagnesemia, myocarditis, and vomiting. Dose interruptions of ENHERTU due to adverse reactions occurred in 23% of patients. Adverse reactions which required dose interruption (>2%) included neutropenia and ILD/pneumonitis. Dose reductions due to an adverse reaction occurred in 11% of patients.

The most common (≥20%) adverse reactions, including laboratory abnormalities, were nausea (61%), decreased white blood cell count (60%), decreased hemoglobin (58%), decreased neutrophil count (52%), decreased lymphocyte count (43%), decreased platelet count (40%), decreased albumin (39%), increased aspartate aminotransferase (35%), increased alanine aminotransferase (34%), fatigue (32%), constipation (31%), decreased appetite (30%), vomiting (26%), increased alkaline phosphatase (22%), and alopecia (21%).

HER2-Positive Locally Advanced or Metastatic Gastric Cancer (6.4 mg/kg)
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 every 3 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) for patients who received ENHERTU.

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 decreased blood potassium. 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 decreased hemoglobin (75%), decreased white blood cell count (74%), decreased neutrophil count (72%), decreased lymphocyte count (70%), decreased platelet count (68%), nausea (63%), decreased appetite (60%), increased aspartate aminotransferase (58%), fatigue (55%), increased blood alkaline phosphatase (54%), increased alanine aminotransferase (47%), diarrhea (32%), decreased blood potassium (30%), vomiting (26%), constipation (24%), increased blood bilirubin (24%), pyrexia (24%), and alopecia (22%).

HER2-Positive (IHC3+) Unresectable or Metastatic Solid Tumors
The safety of ENHERTU was evaluated in 347 adult patients with unresectable or metastatic HER2-positive (IHC3+) solid tumors who received ENHERTU 5.4 mg/kg intravenously once every 3 weeks in DESTINY-Breast01, DESTINY-PanTumor02, DESTINY-Lung01, and DESTINY-CRC02. The median duration of treatment was 8.3 months (range 0.7 to 30.2).

Serious adverse reactions occurred in 34% of patients receiving ENHERTU. Serious adverse reactions in >1% of patients who received ENHERTU were sepsis, pneumonia, vomiting, urinary tract infection, abdominal pain, nausea, pneumonitis, pleural effusion, hemorrhage, COVID-19, fatigue, acute kidney injury, anemia, cellulitis, and dyspnea. Fatalities due to adverse reactions occurred in 6.3% of patients including ILD/pneumonitis (2.3%), cardiac arrest (0.6%), COVID-19 (0.6%), and sepsis (0.6%). The following events occurred in one patient each (0.3%): acute kidney injury, cerebrovascular accident, general physical health deterioration, pneumonia, and hemorrhagic shock.

ENHERTU was permanently discontinued in 15% of patients, of which ILD/pneumonitis accounted for 10%. Dose interruptions due to adverse reactions occurred in 48% of patients. The most frequent adverse reactions (>2%) associated with dose interruption were decreased neutrophil count, anemia, COVID-19, fatigue, decreased white blood cell count, and ILD/pneumonitis. Dose reductions occurred in 27% of patients treated with ENHERTU. The most frequent adverse reactions (>2%) associated with dose reduction were fatigue, nausea, decreased neutrophil count, ILD/pneumonitis, and diarrhea.

The most common (≥20%) adverse reactions, including laboratory abnormalities, were decreased white blood cell count (75%), nausea (69%), decreased hemoglobin (67%), decreased neutrophil count (66%), fatigue (59%), decreased lymphocyte count (58%), decreased platelet count (51%), increased aspartate aminotransferase (45%), increased alanine aminotransferase (44%), increased blood alkaline phosphatase (36%), vomiting (35%), decreased appetite (34%), alopecia (34%), diarrhea (31%), decreased blood potassium (29%), constipation (28%), decreased sodium (22%), stomatitis (20%), and upper respiratory tract infection (20%).

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 after 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 7 months after the last dose. Males: 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. 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 1287 patients with HER2-positive or HER2-low breast cancer treated with ENHERTU 5.4 mg/kg, 22% were ≥65 years and 3.8% were ≥75 years. No overall differences in efficacy within clinical studies 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 (59%) as compared to younger patients (49%). Of the 101 patients with HER2-mutant unresectable or metastatic NSCLC treated with ENHERTU 5.4 mg/kg, 40% were ≥65 years and 8% were ≥75 years. No overall differences in efficacy or safety were observed between patients ≥65 years of age compared to younger patients. Of the 125 patients with HER2-positive locally advanced or metastatic 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. Of the 192 patients with HER2-positive (IHC 3+) unresectable or metastatic solid tumors treated with ENHERTU 5.4 mg/kg in DESTINY-PanTumor02, DESTINY-Lung01, or DESTINY-CRC02, 39% were 65 years or older and 9% were 75 years or older. No overall differences in efficacy or safety were observed between patients ≥65 years of age compared to younger patients.
• Renal Impairment: A higher incidence of Grade 1 and 2 ILD/pneumonitis has been observed in patients with moderate renal impairment. Monitor patients with moderate renal impairment more frequently. The recommended dosage of ENHERTU has not been established for patients with severe renal impairment (CLcr <30 mL/min).
• Hepatic Impairment: In patients with moderate hepatic impairment, due to potentially increased exposure, closely monitor for increased toxicities related to the topoisomerase inhibitor, DXd. The recommended dosage of ENHERTU has not been established for patients with severe hepatic impairment (total bilirubin >3 times ULN and any AST).

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.

Notes

Breast cancer, HER2 expression and brain metastases
Breast cancer is the second most common cancer and one of the leading causes of cancer-related deaths worldwide.¹ More than two million breast cancer cases were diagnosed in 2022 with more than 665,000 deaths globally.¹ While survival rates are high for those diagnosed with early breast cancer, only about 30% of patients diagnosed with or who progress to metastatic disease are expected to live five years following diagnosis.²

HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of many types of tumors, including breast cancer.³ 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.⁴ Approximately one in five cases of breast cancer are considered HER2-positive.⁵

Brain metastases occur when cancer cells spread from their original location to the brain. An estimated 10% to 15% of patients diagnosed with metastatic breast cancer will develop brain metastases.⁶ The risk is higher for those with HER2-positive or triple-negative metastatic breast cancer, with brain metastases occurring in 30% to 50% of these patients.⁷

The median overall survival for patients with breast cancer who have developed brain metastases is eight months; however, this varies based on subtype and the availability of effective treatments.⁸ Current guidelines do not recommend screening patients with breast cancer for brain metastases. As a result, when brain metastases are eventually diagnosed, patients may already present with advanced disease.⁷

DESTINY-Breast12
DESTINY-Breast12 is an open-label, multicenter, Phase IIIb/4 2-cohort, non-comparative clinical trial designed to evaluate the efficacy and safety of ENHERTU (5.4 mg/kg) in patients with previously treated advanced/metastatic HER2-positive breast cancer. The study includes patients without brain metastases (cohort 1) or with brain metastases (cohort 2) who have experienced disease progression following prior anti-HER2-based regimens and have received no more than two lines of therapy in the metastatic setting. Patients were enrolled into one of two cohorts according to the presence or absence of brain metastases at baseline.

The primary endpoint of cohort 1 was ORR as assessed by independent review (non-brain metastases cohort) and the primary endpoint of cohort 2 (brain metastases cohort) was PFS. (Additional endpoints included CNS PFS, CNS ORR, ORR in the brain metastases cohort and safety.)

DESTINY-Breast12 enrolled 504 patients across multiple sites in Asia, Europe, North America and Oceania. 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 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 65 countries 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 65 countries 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 35 countries 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 the US 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 45 countries worldwide for the treatment of adult patients with locally advanced or metastatic HER2-positive (IHC 3+ or 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. Full approval in China for this indication will depend on whether a randomized controlled confirmatory clinical trial can demonstrate clinical benefit in this population.

ENHERTU (5.4 mg/kg) is approved in the US 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 in the US may be contingent upon verification and description of clinical benefit in a confirmatory trial.

ENHERTU development program
A comprehensive global clinical development program is underway evaluating the efficacy and safety of ENHERTU monotherapy across multiple HER2-targetable cancers. Trials in combination with other anti-cancer treatments, such as immunotherapy, also are underway.

Daiichi Sankyo collaboration
AstraZeneca and Daiichi Sankyo entered into a global collaboration to jointly develop and commercialize ENHERTU in March 2019 and 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 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.

With ENHERTU, a HER2-directed antibody drug conjugate (ADC), AstraZeneca and Daiichi Sankyo are aiming to improve outcomes in previously treated HER2-positive and HER2-low 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 goserelin and aims to reshape the HR-positive space with first-in-class AKT inhibitor, capivasertib, and next-generation SERD and potential new medicine camizestrant. AstraZeneca is also collaborating with Daiichi Sankyo to explore the potential of TROP2-directed ADC, datopotamab deruxtecan, in this setting.

PARP inhibitor 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 olaparib in these settings and to explore its potential in earlier disease.

To bring much-needed treatment options to patients with triple-negative breast cancer, an aggressive form of breast cancer, AstraZeneca is evaluating the potential of datopotamab deruxtecan alone and in combination with immunotherapy durvalumab, capivasertib in combination with chemotherapy, and durvalumab in combination with other oncology medicines, including olaparib and ENHERTU.

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 catalyze 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 is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialization of prescription medicines in Oncology, Rare Diseases and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 125 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 social media @AstraZeneca.

References

1. Bray F, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024 Apr 4. doi: 10.3322/caac.21834.
2. National Cancer Institute. Surveillance, Epidemiology and End Results Program. Available at: https://seer.cancer.gov/statfacts/html/breast-subtypes.html. Accessed September 2024.
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 Nov 1;123(21):4099-4105.
5. 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.
6. Simsek M, et al. Breast Cancer Patients with Brain Metastases: A Cross-Sectional Study. Breast J. 2022; 19;2022:5763810.
7. Kuksis M, et al. The incidence of brain metastases among patients with metastatic breast cancer: a systematic review and meta-analysis. Neuro Oncol. 2021 Jun 1;23(6):894-904.
8. Bailleux C, et al. Treatment strategies for breast cancer brain metastases. Br J Cancer. 2021 Jan;124(1):142-155.

US-93549 Last Updated 9/24

View source version on businesswire.com: https://www.businesswire.com/news/home/20240913294257/en/

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FAQ

What was the progression-free survival rate for ENHERTU (AZN) in patients with HER2-positive metastatic breast cancer and brain metastases?

The DESTINY-Breast12 trial showed a 61.6% progression-free survival rate at 12 months for ENHERTU in patients with HER2-positive metastatic breast cancer and brain metastases.

What was the CNS progression-free survival rate for ENHERTU (AZN) in patients with brain metastases?

The trial demonstrated a 58.9% CNS progression-free survival rate at 12 months for ENHERTU in patients with HER2-positive metastatic breast cancer and brain metastases.

What was the objective response rate for ENHERTU (AZN) in patients without brain metastases in the DESTINY-Breast12 trial?

In patients without brain metastases, ENHERTU achieved a 62.7% objective response rate, including 23 complete responses and 128 partial responses.

What was the incidence of interstitial lung disease (ILD) or pneumonitis in the DESTINY-Breast12 trial for ENHERTU (AZN)?

ILD or pneumonitis occurred in 12.9% of patients without brain metastases and 16.0% of patients with brain metastases treated with ENHERTU.