Daiichi Sankyo announced that the first patient was dosed in the global DestinyBreast11 phase 3 trial evaluating the efficacy and safety of Enhertu (trastuzumab deruxtecan), a HER2 directed antibody drug conjugate (ADC) being jointly developed by Daiichi Sankyo and AstraZeneca, as a neoadjuvant therapy in patients with high-risk HER2 positive early-stage breast cancer.

Destiny-Breast11 will evaluate Enhertu as a monotherapy or Enhertu followed by paclitaxel, trastuzumab and pertuzumab (THP) compared to the standard of care regimen of doxorubicin and cyclophosphamide followed by paclitaxel, trastuzumab and pertuzumab (ddAC-THP) in patients with highrisk (lymph node positive [N1-3] or with a primary tumor stage T3-4), locally advanced or inflammatory, HER2 positive early-stage breast cancer.

Breast cancer is the most common cancer worldwide with more than two million cases diagnosed in 2020, resulting in nearly 685,000 deaths globally. About 60% of women with breast cancer are diagnosed with early-stage breast cancer. The current standard of care in the neoadjuvant setting of HER2 positive early stage breast cancer consists of a multi-agent regimen of dual HER2 targeted therapy with three different chemotherapy agents. While the goal of this regimen is to achieve a pathologic complete response (pCR), or the absence of active cancer cells prior to surgery, it is associated with significant toxicity.

Additionally, some patients will experience disease relapse or progression. Replacing the standard of care with Enhertu or displacing anthracyclines with Enhertu followed by THP may potentially improve outcomes and could reduce treatment burden and overall toxicity in patients not benefiting from standard of care therapy.

“Destiny-Breast11 is the first trial to evaluate Enhertu in the neoadjuvant setting in patients with highrisk HER2 positive early-stage breast cancer,” said Gilles Gallant, BPharm, PhD, FOPQ, Senior Vice President, Global Head, Oncology Development, Oncology R&D, Daiichi Sankyo. “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 anthracylinesin the neoadjuvant setting.”