A Randomized, Open-Label, Multicenter Phase III Clinical Study of SHR-A1811 Monotherapy Versus Docetaxel + Carboplatin + Trastuzumab + Pertuzumab as Neoadjuvant Treatment in Previously Untreated Early or Locally Advanced HER2-Positive Breast Cancer

INTERVENTION: Trial group (SHR‐A1811 monotherapy group):SHR‐A1811 (4.8 mg/kg q3w), once every 3 weeks for 8 cycles;Control group (TCbHP therapy group):Docetaxel (75 mg/m^2 q3w) + Carboplatin (AUC=6 q3w) + Trastuzumab (initial dose 8 mg/kg, then 6 mg/kg q3w) + Pertuzumab (initial dose 840 mg, then 420 mg q3w), once every 3 weeks for 6 cycles; CONDITION: Breast cancer PRIMARY OUTCOME: TpCR as assessed by the IRC, defined as the absence of residual invasive cancer in hematoxylin and eosin (H&E)‐stained sections of the resected breast specimen and all sampled ipsilateral lymph nodes; SECONDARY OUTCOME: TpCR assessed by the central pathology laboratory of participating study sites.;Event‐free survival (EFS);Distant metastasis‐free survival (DDFS);Safety endpoint;Objective response rate (ORR) assessed preoperatively according to the Efficacy Evaluation Criteria in Solid Tumors (RECIST v1.1);Disease‐free survival (DFS); INCLUSION CRITERIA: 1. Female treatment‐naïve patients aged >=18 and <=75 years old; 2. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1; 3. Breast cancer meeting all of the following criteria (all pathological evaluations must be based solely on the pathology diagnostic report from the study site or the study site's review results of non‐study site pathological tissue samples/slides, with adequate tissue samples available for assessment): (1) Histologically confirmed invasive breast cancer with at least one lesion >2 cm in diameter; (2) Clinical tumor stage: Stage II (T2N0‐1M0/T3N0M0) or Stage III (T2N2‐3M0/T3N1‐3M0); (3) Pathologically confirmed HER2‐positive breast cancer, defined as: HER2 immunohistochemistry (IHC) 3+, or HER2 IHC 2+ with positive in situ hybridization (ISH) result; (4) For clinically diagnosed multifocal or multicentric breast cancer, all lesions must meet the above pathological and immunohistochemical criteria; (5)