這是一項第三期、兩臂、隨機、雙盲、安慰劑對照研究，對象為接受術前化療及 HER2 導向治療（包括 trastuzumab）後進行手術，並發現乳房及／或腋窩淋巴結有殘留侵襲性疾病的 HER2 陽性原發性乳癌患者。 截至 2024 年 6 月 4 日，本研究不再接受任何新篩查的患者。
適應症：Breast Cancer
收案條件
納入條件
- Histologically confirmed invasive breast carcinoma
- Centrally-confirmed human epidermal growth factor receptor 2 (HER2)-positive invasive breast cancer
- Centrally confirmed PD-L1 and hormone receptor status
- Clinical stage at disease presentation (prior to neoadjuvant therapy): cT4/anyN/M0, any cT/N2-3/M0, or cT1-3/N0-1/M0 (participants with cT1mi/T1a/T1b/N0 are not eligible)
- Completion of pre-operative systemic chemotherapy including at least 9 weeks of taxane and 9 weeks of trastuzumab (anthracycline and/or additional HER2-targeted agents are permitted)
- \<=12 weeks between primary surgery and randomization
- Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1
- Screening left ventricular ejection fraction (LVEF) \>= 50% and no decrease in LVEF by \>15% from the pre-chemotherapy LVEF. If no pre-chemotherapy LVEF, screening LVEF \>= 55%
- Life expectancy \>= 6 months
- Adequate hematologic and end organ function
排除條件
- Stage IV breast cancer
- An overall response of disease progression according to the investigator at the conclusion of preoperative systemic therapy
- Prior treatment with T-DM1, or atezolizumab, or other immune checkpoint inhibitors
- History of exposure to various cumulative doses of anthracyclines
- History of other malignancy within 5 years prior to screening, except for appropriately treated carcinoma in situ of the cervix, non-melanoma skin carcinoma, Stage I uterine cancer, or ductal carcinoma in situ (DCIS)
- Current grade \>=2 peripheral neuropathy
- History of idiopathic pulmonary fibrosis, organizing pneumonia, or pneumonitis
- History of or active autoimmune disease or immune deficiency
- Treatment with immunostimulatory or immunosuppressive agents
- Cardiopulmonary dysfunction
- Any known active liver disease
收案條件維持 ClinicalTrials.gov 原始英文登錄資料，實際收案資格以研究團隊的正式評估與受試者同意書為準。資料來源：ClinicalTrials.gov，每兩週自動更新，最後同步：2026年10月8日。