Alphamab Oncology (HKEX: 9966) revealed that anbenitamab (KN026), a bispecific anti-HER2 antibody, met its primary endpoint in the Phase III Neo-Healer trial evaluating neoadjuvant treatment of early or locally advanced HER2-positive breast cancer, with the company describing the total pathological complete response (tpCR) result as both statistically and clinically significant versus the current standard of care.
Neo-Healer (KN026-004) is a randomized, open-label, multicenter Phase III study planned to enroll approximately 520 patients with early or locally advanced HER2+ breast cancer, assigned 1:1 to receive KN026 plus albumin-bound docetaxel (HB1801) ± carboplatin or trastuzumab plus pertuzumab plus docetaxel ± carboplatin, with total pathological complete response assessed by a blinded independent review committee as the primary endpoint.
No numerical tpCR rates, confidence intervals, or p-values were disclosed. The announcement stated only that KN026 in combination with HB1801 ± carboplatin "significantly improved" tpCR compared with the standard regimen, with full data to be presented at an international conference. The absence of quantitative results limits any assessment of effect size at this stage. Safety data were not reported.
Alphamab's HER2 bispecific engineering
Anbenitamab is engineered using Alphamab's CRIB (Charge Repulsion Induced Bispecific) platform and binds two non-overlapping epitopes on HER2 simultaneously, blocking downstream signaling while enhancing antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and receptor downregulation. The design effectively consolidates the biological roles of trastuzumab and pertuzumab — which target distinct HER2 epitopes — into a single molecule. The experimental arm also replaces standard docetaxel with HB1801, CSPC Group's albumin-bound docetaxel formulation, which encapsulates the active drug in human serum albumin, eliminating the polysorbate 80 and ethanol solvents associated with hypersensitivity reactions and premedication requirements.
Competitive context
The neoadjuvant HER2+ breast cancer setting is one where the limitations of current therapy are quantifiable. Trastuzumab plus pertuzumab combined with chemotherapy — the THP/TCbHP regimen — achieves tpCR in roughly half of patients with early or locally advanced disease. Patients who do not achieve tpCR face a materially worse prognosis and are typically escalated to adjuvant ado-trastuzumab emtansine (T-DM1). A bispecific antibody that raises the tpCR ceiling would, in principle, reduce downstream escalation requirements, though the Neo-Healer data needed to substantiate that argument have not yet been released.