Alphamab Oncology announced that the first patient has been dosed in the Phase III clinical study (KN026-007) of HER2 bispecific antibody Anbenitamab (KN026) in combination with albumin-bound docetaxel (HB1801) and chemotherapy as adjuvant treatment for HER2-positive breast cancer (BC). Anbenitamab (KN026) is independently developed by the Company, and co-developed with JMT-Bio Technology Co., Ltd., a wholly-owned subsidiary of CSPC Pharmaceutical Group Co., Ltd. (stock code: 1093.HK).

Breast cancer is the most common malignant tumor among women in China, with the HER2-positive subtype accounting for approximately 20% to 30% of all cases. Although trastuzumab (with or without pertuzumab) combined with chemotherapy has significantly reduced the risk of recurrence, subgroup analyses from multiple clinical studies indicate that patients with HER2-positive BC who are lymph node-positive, particularly those with four or more positive lymph nodes, continue to face a high risk of recurrence. Compared with regimens containing trastuzumab alone, dual-targeted therapy combined with chemotherapy as adjuvant treatment for HER2-positive BC can further reduce the risk of recurrence, with the most pronounced benefit observed in lymph node-positive patients. Accordingly, the exploration of more effective adjuvant treatment strategies to improve long-term outcomes for this patient population is of significant clinical importance.

KN026-007 is a randomized, controlled, open-label, multicenter Phase III clinical study, which is expected to enroll approximately 1,800 patients with resectable HER2-positive BC who have histologically confirmed involvement of four or more regional lymph nodes following surgery. Eligible patients will be randomized in a 1:1 ratio, aiming to compare the efficacy and safety of Anbenitamab in combination with HB1801 and chemotherapy versus trastuzumab plus pertuzumab in combination with chemotherapy as adjuvant treatment. The primary endpoint of the study 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.