This is a prospective, open-label, multicenter, single-arm clinical study designed to compare the efficacy and safety of neoadjuvant treatment with T-DXd in combination with an immune checkpoint inhibitor in patients with primary intermediate- to high-risk HR-positive, HER2-overexpressing early-stage breast cancer.
Adults between the ages of 18 and 70 at the time of signing the informed consent form.
An Eastern Cooperative Oncology Group (ECOG) score of 0 to 1.
Previously untreated, operable invasive breast cancer measuring greater than 2.0 centimeters (cT2) with positive clinical lymph nodes (cN1/cN2); or clinically staged T3-T4, clinically lymph node-negative (N0) or clinically lymph node-positive (cN1/cN2) without distal metastases.
Tumors with low levels of HER2 expression by immunohistochemistry (IHC), defined as IHC 1+ or IHC 2+ and FISH negative.
Stage IV (metastatic) breast cancer and bilateral breast cancer
Previous history of invasive breast cancer.
Previous history of ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS)
Other malignant tumors within 5 years, excluding cured carcinoma in situ of the cervix and non-melanoma skin cancers.