SHR-A1811 Versus Trastuzumab Plus Pertuzumab in ctDNA-Positive HER2-Positive Early Breast Cancer After Pathologic Complete Response

This investigator-initiated, single-center, randomized, open-label, phase II trial will evaluate the efficacy and safety of intensified adjuvant SHR-A1811 compared with trastuzumab plus pertuzumab in women with initially stage IIB-IIIC HER2-positive early breast cancer who achieved pathologic complete response after neoadjuvant systemic therapy and have detectable postoperative circulating tumor DNA (ctDNA). Eligible participants will be randomized 1:1 and stratified by hormone receptor status, HER2 test category, and initial clinical anatomic stage. The primary endpoint is invasive disease-free survival.