ALPHAMAB-B (09966) announced that the first patient has been dosed in a Phase III clinical study (Study Number: KN026-007) evaluating KN026 in combination with docetaxel (albumin-bound) (HB1801) and chemotherapy as an adjuvant treatment for human epidermal growth factor receptor 2 (HER2) positive (HER2+) breast cancer (BC). The study is being developed in collaboration with Shanghai Jinmante Biotechnology Co., Ltd., a subsidiary of CSPC Pharmaceutical Group Limited (Stock Code: 1093). Breast cancer is the most common malignant tumor among women in China, with the HER2+ subtype accounting for approximately 20% to 30% of cases. Although trastuzumab (with or without pertuzumab) combined with chemotherapy has significantly reduced the risk of recurrence for patients, subgroup analyses from multiple clinical studies indicate that HER2+ BC patients with lymph node positivity, particularly those with ≥4 positive lymph nodes, continue to face a high risk of recurrence. Dual-targeted therapy combined with chemotherapy as an adjuvant treatment for HER2+ BC, compared to regimens containing only trastuzumab, can further reduce the risk of recurrence, with the most significant benefit observed in the lymph node-positive population. Therefore, exploring superior adjuvant treatment strategies to improve long-term outcomes for this patient population holds significant clinical importance. KN026-007 is a randomized, controlled, open-label, multi-center Phase III clinical study expected to enroll approximately 1,800 patients with resectable HER2+ BC who have been histologically confirmed post-surgery to have ≥4 positive regional lymph nodes. Eligible patients will be randomized in a 1:1 ratio. The study aims to compare the efficacy and safety of KN026 combined with HB1801 and chemotherapy versus trastuzumab combined with pertuzumab and chemotherapy as adjuvant treatments. The primary endpoint is investigator-assessed invasive disease-free survival (iDFS). Secondary endpoints include disease-free survival (DFS), recurrence-free interval (RFI), distant recurrence-free interval (DRFI), overall survival (OS), safety, pharmacokinetics, and immunogenicity.