AstraZeneca and Daiichi Sankyo's Enhertu Receives EU Approval as Monotherapy for Unresectable or Metastatic HER2-Positive Breast Cancer

Strategic Insights -

AstraZeneca and Daiichi Sankyo's Enhertu (trastuzumab deruxtecan) has secured European Union (EU) approval 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. The approval by the European Commission (EC) is based on the positive opinion of the Committee for Medicinal Products for Human Use and follows the publication of results from the DESTINY-Breast03 Phase III trial in The New England Journal of Medicine.

Key Takeaways:

  • Enhertu has been approved in the EU as a monotherapy for unresectable or metastatic HER2-positive breast cancer patients who have received one or more prior anti-HER2-based regimens.
  • The approval is based on the DESTINY-Breast03 Phase III trial, which demonstrated a 72% reduction in the risk of disease progression or death for Enhertu compared to trastuzumab emtansine (T-DM1).
  • Secondary endpoint results showed a strong trend towards improved overall survival with Enhertu, with 96.1% of patients alive at nine months compared to 91.3% for T-DM1.
  • Confirmed objective response rate was more than doubled in the Enhertu arm versus the T-DM1 arm (79.7% vs 34.2%).
  • The most common adverse reactions included 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, with no Grade 4 cases occurring.
  • The European Society for Medical Oncology Clinical Practice Guidelines were updated in October 2021 to recommend Enhertu as the preferred second-line therapy for HER2-positive metastatic breast cancer patients.

Statistics:

  • 96.1% of patients treated with Enhertu were alive at nine months
  • 91.3% of patients treated with T-DM1 were alive at nine months
  • Confirmed objective response rate was 79.7% in the Enhertu arm
  • Confirmed objective response rate was 34.2% in the T-DM1 arm
  • 77.0% of patients experienced nausea
  • 57.2% of patients experienced fatigue
  • 46.8% of patients experienced vomiting
  • 38.0% of patients experienced alopecia
  • 34.6% of patients experienced neutropenia
  • 12.0% of patients experienced interstitial lung disease (ILD) or pneumonitis

Sources:

  • AstraZeneca, website: http://www.astrazeneca.com
  • The New England Journal of Medicine, DESTINY-Breast03 Phase III trial results
  • European Society for Medical Oncology Clinical Practice Guidelines, October 2021