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

Patients who have completed neoadjuvant systemic therapy and curative breast and axillary surgery with ypT0/is ypN0 disease will undergo postoperative ctDNA testing 14 to 42 days after the last definitive surgery and before initiation of adjuvant systemic therapy. Participants with ctDNA positivity and no clinical or radiographic evidence of recurrent or metastatic disease will be randomized to SHR-A1811 or trastuzumab plus pertuzumab. Post-randomization ctDNA results will not be used for clinical management and will remain blinded to investigators and participants until the primary analysis database is locked, unless a future ethics-approved protocol amendment specifies otherwise.