ALPHAMAB-B (09966) has announced that the New Drug Application (NDA) for anitumomab (trade name: Enituo, development code: KN026) in combination with docetaxel injection (albumin-bound) (HB1801) for the first-line treatment of unresectable or metastatic HER2-positive (HER2+) adult breast cancer has been accepted by China's National Medical Products Administration (NMPA) and granted priority review status.

This combination therapy, co-developed with Shanghai Jinmante Biotech, a subsidiary of CSPC Pharmaceutical Group (1093), had previously received breakthrough therapy designation from the NMPA for this indication. The NDA submission is primarily based on results from the pivotal Phase III clinical study (study number: KN026-003/Healer).

The study findings demonstrated that the combination of anitumomab and HB1801 as a first-line treatment for HER2+ advanced breast cancer significantly improved progression-free survival (PFS) compared to the current standard of care, trastuzumab plus pertuzumab and docetaxel (THP regimen), with the superiority showing significant statistical meaning and clear clinical benefit. The overall safety profile was favorable. Detailed data from the study will be presented at an international academic conference in the near future.

In China, approximately 20% of breast cancer patients are already at an advanced stage at initial diagnosis, and around 10% of HER2+ early-stage breast cancer patients experience disease recurrence within three years after curative surgery. The THP regimen remains the preferred first-line treatment for HER2+ advanced breast cancer both domestically and internationally. Although this regimen has significantly extended PFS for these patients, about 50% still experience disease progression within two years, leaving substantial unmet clinical needs.

The KN026-003/Healer study is the world's first Phase III trial in HER2+ advanced breast cancer to conduct a head-to-head comparison of a HER2 bispecific antibody combination therapy and confirm superior efficacy over the THP regimen, achieving a historic breakthrough in the first-line treatment landscape for HER2+ advanced breast cancer. This development holds promise for offering Chinese patients with HER2+ advanced breast cancer a new treatment option with improved efficacy, a favorable safety profile, and greater dosing convenience.

Currently, the combination therapy of anitumomab and HB1801 has completed a full-course clinical layout covering neoadjuvant, adjuvant, and advanced first-line treatment for HER2+ breast cancer. Additionally, the NDA for this combination therapy in the neoadjuvant setting for early or locally advanced HER2+ adult breast cancer has also been accepted by the NMPA and included in the priority review process.