Daiichi Sankyo Company has dosed the first participant in the Phase III DESTINY‑Breast11 trial of Enhertu (trastuzumab deruxtecan) in breast cancer patients.

The trial will assess the treatment as a neoadjuvant therapy for high-risk human epidermal growth factor receptor 2 (HER2) positive early-stage breast cancer patients.

Being developed by Daiichi Sankyo in collaboration with AstraZeneca , Enhertu is a HER2-directed antibody-drug conjugate (ADC).

It is designed with Daiichi Sankyo’s DXd ADC technology.

The global, open-label, randomised trial will assess the safety and efficacy of Enhertu 5.4mg/kg alone or Enhertu followed by THP versus standard care regimen (ddAC-THP) in HER2-positive early breast cancer patients.

In this study, subjects will be randomised in a 1:1:1 ratio for treatment with either eight cycles of Enhertu alone, or four cycles of Enhertu followed by four THP cycles.

The subjects will also receive four cycles of ddAC and THP.

Daiichi Sankyo Oncology R&D Oncology Development senior vice-president, global head Gilles Gallant said: “DESTINY-Breast11 is the first trial to evaluate ENHERTU in the neoadjuvant setting in patients with high-risk HER2 positive early-stage breast cancer.

“The goal of this study is to determine if ENHERTU alone or followed by chemotherapy can potentially replace the current standard of care or displace the use of anthracyclines in the neoadjuvant setting.”

The pathologic complete response (pCR), which includes an absence of invasive disease in the breast and lymph nodes, will be the trial’s primary goal.

Invasive disease-free survival, pharmacokinetics, event-free survival, overall survival, immunogenicity, and safety will be assessed as the secondary endpoints of the trial.

Furthermore, the DESTINY-Breast11 trial will enrol nearly 624 participants at various centres across South America, North America, Europe, and Asia.

In August, Daiichi Sankyo and AstraZeneca reported positive data from the Phase III DESTINY-Breast03 clinical trial of Enhertu in patients with HER2-positive, unresectable and/or metastatic breast cancer.