Neoadjuvant Pertuzumab Biosimilar HLX11 Versus Reference Pertuzumab for Early-stage or Locally Advanced Breast Cancer: A phase 3 Equivalence Trial
In brief
Pertuzumab biosimilar HLX11 achieves same 46% complete-response rate as reference
In a double-blind phase 3 trial of 908 HER2-positive, hormone-receptor-negative breast cancer patients, neoadjuvant HLX11 produced a total pathological complete response of 46.3%, virtually identical to the 45.8% seen with EU-sourced pertuzumab, meeting predefined equivalence criteria. Safety, drug levels and immune reactions were also comparable, supporting HLX11 as an interchangeable option.
- Journal
- Clinical cancer research : an official journal of the American Association for Cancer Research (Q1)
- Published
- 9 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Jin Zhang, Jinhai Zhu, Yaping Yang, Dong Song, Tao Huang, Xiaopeng Ma, et al.
- PMID
- 42714872
- DOI
- 10.1158/1078-0432.CCR-26-1604
Why clinicians should know about it
- Picked for Surgical Oncology (top studies of the week, 18 October 2026): Neoadjuvant pertuzumab biosimilar trial for HER2+ breast cancer, surgical endpoint
Abstract
PURPOSE: This randomized, double-blind phase 3 equivalence study aimed to evaluate the similarity of neoadjuvant pertuzumab biosimilar HLX11 versus reference pertuzumab plus trastuzumab and docetaxel for human epidermal growth factor receptor 2-positive, hormone receptor-negative early-stage or locally advanced breast cancer (BC). PATIENTS AND METHODS: Eligible patients were randomly assigned (1:1) to receive 4 cycles of neoadjuvant HLX11 (HLX11 arm) or European Union-sourced pertuzumab, plus trastuzumab and docetaxel (EU-pertuzumab arm). Patients in the respective arms received adjuvant HLX11 plus trastuzumab or were re-randomized (1:1) to receive HLX11 or EU-pertuzumab plus trastuzumab. The primary endpoint was blinded independent central review (BICR)-assessed total pathological complete response (tpCR) rate. RESULTS: In total, 908 patients were randomized to the HLX11 (n = 454) or EU-pertuzumab arm (n = 454); 192 patients in HLX11 arm received adjuvant HLX11; 200 patients in EU-pertuzumab arm were re-randomized to receive adjuvant HLX11 (n = 100) or EU-pertuzumab (n = 100). BICR-assessed tpCR rate (95% confidence interval [CI]) was 46.3% (41.6%-51.0%) and 45.8% (41.2%-50.5%), respectively. The equivalence criteria were met, with relative risk of tpCR (90% CI) of 1.01 (0.90-1.14) and relative difference (95% CI) of 0.47% (-5.99%-6.92%). No clinically meaningful differences were observed in other efficacy endpoints, safety, pharmacokinetics (PK), or immunogenicity. In the adjuvant phase, switching from EU-pertuzumab to HLX11 led to no notable differences in safety, PK, or immunogenicity. CONCLUSIONS: Compared with EU-pertuzumab, neoadjuvant HLX11 demonstrated a similar tpCR rate and no clinically meaningful differences in other efficacy endpoints, safety, PK, or immunogenicity in BC.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.