Alphamab-B (09966) has announced that the Phase III clinical study (Study Code: KN026-003) for the investigational drug Ennituo (generic name: Anituo Monoclonal Antibody, R&D code: KN026) in combination with an albumin-bound docetaxel injection (HB1801) as a first-line treatment for HER2-positive advanced breast cancer has successfully met its pre-specified primary endpoint of Progression-Free Survival (PFS).

The study, conducted in collaboration with Shanghai Jinmante Biotechnology Co., Ltd., a subsidiary of CSPC Pharmaceutical Group Limited (Stock Code: 1093), was evaluated by an Independent Data Monitoring Committee (IDMC). The results demonstrated both statistically significant and clinically meaningful benefits.

Breast cancer ranks among the most prevalent malignancies in Chinese women, with the HER2-positive subtype accounting for approximately 20% to 30% of cases. In China, around 20% of breast cancer patients are diagnosed at an advanced stage, and about 10% of patients with early-stage HER2-positive breast cancer experience disease recurrence within three years after curative surgery.

The current standard first-line treatment for HER2-positive advanced breast cancer, both domestically and internationally, remains the THP regimen, which combines trastuzumab, pertuzumab, and docetaxel. While this treatment has significantly extended PFS for such patients, approximately 50% still experience disease progression within two years, highlighting a significant unmet clinical need.

KN026-003 is a randomized, controlled, open-label, multi-center Phase III study designed to enroll approximately 880 patients with HER2-positive advanced breast cancer. Participants were randomized in a 1:1 ratio to compare the efficacy and safety of KN026 combined with HB1801 versus the THP regimen for first-line treatment. The primary endpoint was PFS as assessed by a Blinded Independent Review Committee (BIRC).

According to the IDMC assessment, the combination of KN026 and HB1801 significantly extended patient PFS and reduced the risk of disease progression or death compared to the THP regimen. The data also showed a favorable trend towards overall survival (OS) benefit. Detailed results from the study are expected to be presented at an upcoming international academic conference.