Approval broadens indication for AstraZeneca and Daiichi Sankyo’s Enhertu across Europe to earlier use in HER2-positive metastatic breast cancer
Based on ground-breaking DESTINY-Breast03 results in which Enhertu demonstrated a 72% reduction in the risk of disease progression or death vs. trastuzumab emtansine
AstraZeneca and Daiichi Sankyo’s Enhertu (trastuzumab deruxtecan) has been approved in the European Union (EU) as a monotherapy for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received one or more prior anti-HER2-based regimens.
Enhertu is a specifically engineered HER2-directed antibody drug conjugate (ADC) being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.
The approval by the European Commission (EC) follows the positive opinion of the Committee for Medicinal Products for Human Use and is based on results from the DESTINY-Breast03 Phase III trial, which were published in The New England Journal of Medicine.1 In the trial, Enhertu reduced the risk of disease progression or death by 72% versus trastuzumab emtansine (T-DM1) (hazard ratio [HR] 0.28; 95% confidence interval [CI] 0.22-0.37; p<0.000001) in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane.
In Europe, more than 530,000 patients are diagnosed with breast cancer each year.2 Approximately one in five patients with breast cancer are considered HER2-positive.3 Despite initial treatment with trastuzumab, pertuzumab and a taxane, patients with HER2-positive metastatic breast cancer will often experience disease progression.4,5
Additional results from the DESTINY-Breast03 Phase III trial showed that in the secondary endpoint of overall survival (OS), there was a strong trend towards improved OS with Enhertu (HR 0.55; 95% CI 0.36-0.86), however this analysis is not yet mature and further follow-up is ongoing. Nearly all patients (96.1%) treated with Enhertu were alive at nine months compared to 91.3% of patients treated with T-DM1. Confirmed objective response rate (ORR) was more than doubled in the Enhertu arm versus the T-DM1 arm (79.7% vs. 34.2%).
The safety of Enhertu has been evaluated in a pooled analysis of 573 patients across multiple tumour types who had received at least one dose of Enhertu (5.4 mg/kg) in clinical trials. The most common adverse reactions were nausea (77.0%), fatigue (57.2%), vomiting (46.8%), alopecia (38.0%) and neutropenia (34.6%). Cases of interstitial lung disease (ILD) or pneumonitis were reported in 12.0% of patients. Most ILD cases were Grade 1 (2.6%) and Grade 2 (7.3%). Grade 3 cases occurred in 0.7% of patients, no Grade 4 cases occurred, and Grade 5 cases occurred in 1.4% of patients.
Based on the results of DESTINY-Breast03, the European Society for Medical Oncology Clinical Practice Guidelines were updated in October 2021 to recommend Enhertu for use as the preferred second-line therapy for patients with HER2-positive metastatic breast cancer following progression with a taxane and trastuzumab.6
As part of this approval, the EC has also extended the market protection period for Enhertu in this setting by one extra year based on the significant clinical benefit compared to existing approved therapies.
HER2-positive breast cancer
Breast cancer is the most common cancer and is one of the leading causes of cancer-related deaths worldwide.7 More than two million patients were diagnosed with breast cancer in 2020, with nearly 685,000 deaths globally.7 In Europe, more than 530,000 patients are diagnosed with breast cancer each year.2 Approximately one in five patients with breast cancer are considered HER2-positive.3
HER2 is a tyrosine kinase receptor, growth-promoting protein expressed on the surface of many types of tumours including breast, gastric, lung and colorectal cancers.8 HER2 protein overexpression may occur as a result of HER2 gene amplification and is often associated with aggressive disease and poor prognosis in breast cancer.9
Despite initial treatment with trastuzumab, pertuzumab and a taxane, patients with HER2-positive metastatic breast cancer will often experience disease progression.4,5 More treatment options are needed to further delay progression and extend survival.4,10,11
Enhertu is a HER2-directed ADC. Designed using Daiichi Sankyo’s proprietary DXd ADC technology, Enhertu is the lead ADC in the oncology portfolio of Daiichi Sankyo and the most advanced programme in AstraZeneca’s ADC scientific platform. Enhertu consists of a HER2 monoclonal antibody attached to a topoisomerase I inhibitor payload, an exatecan derivative, via a stable tetrapeptide-based cleavable linker.
Enhertu (5.4mg/kg) is approved in more than 30 countries for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received a (or one or more) prior anti-HER2-based regimen either in the metastatic setting, or in the neoadjuvant or adjuvant setting and have developed disease recurrence during or within six months of completing therapy, based on the results from the DESTINY-Breast03 trial.
Enhertu (5.4mg/kg) is also approved in several countries 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 based on the results from the DESTINY-Breast01 trial.
Enhertu (6.4mg/kg) is approved in several countries for the treatment of adult patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received a prior trastuzumab-based regimen based on the results from the DESTINY-Gastric01 trial.
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide.