CSPC Pharmaceutical Group (HKEX: 1093) reported Phase III data showing that anbenitamab (Ennituo), its HER2 bispecific antibody co-developed with Jiangsu Alphamab Biopharmaceuticals, produced a pathological complete response rate of 62.4% in HER2-positive breast cancer patients receiving neoadjuvant therapy. Given the significance of the performance at 11 percentage points above the standard dual-blockade regimen, the data were selected for a late-breaking oral presentation at the 2026 ASCO Annual Meeting.
The Neo-Healer trial (KN026–004) is a randomized, open-label, multicentre Phase III study that enrolled 521 patients with early and locally advanced HER2-positive breast cancer and assigned them 1:1 to either anbenitamab plus HB1801 (albumin-bound docetaxel) ± carboplatin, or the standard THP regimen — Roche's Herceptin (trastuzumab) plus Roche's Perjeta (pertuzumab) plus docetaxel ± carboplatin — for six cycles. The primary endpoint was total pathological complete response (tpCR) assessed by a blinded independent review committee.
The experimental arm achieved a BIRC-assessed tpCR of 62.4% (95% CI: 56.2–68.2) versus 51.2% (95% CI: 44.9–57.4) in the control arm (one-sided p=0.0036). Investigator-assessed tpCR tracked closely at 63.9% versus 51.2% (p=0.0011), and breast pathological complete response by BIRC reached 64.6% versus 55.0% (p=0.0099). The tpCR advantage was consistent across carboplatin and non-carboplatin subgroups, as well as across hormone receptor status and clinical stage strata. On safety, Grade ≥3 treatment-emergent adverse events occurred in 29.3% of the experimental group and 28.3% of the control group, with no new safety signals identified and no apparent additive toxicity. The dominant toxicities were haematological and gastrointestinal, consistent with the known profiles of each individual agent.