ALPHAMAB-B(09966): The phase III clinical study of Anituximab (KN026) as first-line treatment for HER2-positive advanced breast cancer has reached the primary endpoint.

ALPHAMAB-B (09966) announced that the Phase III clinical study (study code: KN026-003) of the combination therapy of ALPHAMAB-B s anti-HER2 antibody KN026 (trade name: Ennitux) and albumin-bound paclitaxel (HB1801) for first-line treatment of human epidermal growth factor receptor 2 (HER2) positive (HER2+) advanced breast cancer, developed in collaboration with CSPC PHARMA's subsidiary Shanghai Jintan BioTech Co., Ltd. (Jintan BioTech), has successfully met the pre-defined primary endpoint of progression-free survival (PFS) as assessed by the Independent Data Monitoring Committee (IDMC), with statistically significant and clinically meaningful results. Breast cancer is one of the most common malignant tumors among Chinese women, with the HER2+ subtype accounting for approximately 20%-30%. In China, about 20% of breast cancer patients are diagnosed at an advanced stage, while about 10% of HER2+ early breast cancer patients experience disease recurrence within 3 years after curative surgery. The combination therapy of trastuzumab plus pertuzumab and paclitaxel (THP regimen) remains the preferred first-line treatment for HER2+ advanced breast cancer both domestically and internationally. Despite significantly prolonging the PFS of patients receiving this treatment, approximately 50% of patients still experience disease progression within 2 years, indicating an unmet clinical need. The KN026-003 study is a randomized, controlled, open-label, multicenter Phase III clinical trial planned to enroll approximately 880 patients with HER2+ advanced breast cancer. Patients will be randomized in a 1:1 ratio to receive either the KN026 in combination with HB1801 or the THP regimen, with the main endpoint being PFS evaluated by the Blind Independent Review Committee (BIRC). The IDMC evaluation showed that the combination of KN026 and HB1801 significantly prolonged the PFS of patients, reduced the risk of disease progression or death, and showed a trend towards overall survival (OS) benefit. Detailed data from this study will be presented at an upcoming international academic conference.