A Biparatopic HER2-Targeting Antibody-Drug Conjugate Induces Tumor Regression in Primary Models Refractory to or Ineligible for HER2-Targeted Therapy

Cancer Cell. 2016 Jan 11;29(1):117-29. doi: 10.1016/j.ccell.2015.12.008.


Antibody-drug conjugate (ADC) which delivers cytotoxic drugs specifically into targeted cells through internalization and lysosomal trafficking has emerged as an effective cancer therapy. We show that a bivalent biparatopic antibody targeting two non-overlapping epitopes on HER2 can induce HER2 receptor clustering, which in turn promotes robust internalization, lysosomal trafficking, and degradation. When conjugated with a tubulysin-based microtubule inhibitor, the biparatopic ADC demonstrates superior anti-tumor activity over ado-trastuzumab emtansine (T-DM1) in tumor models representing various patient subpopulations, including T-DM1 eligible, T-DM1 ineligible, and T-DM1 relapsed/refractory. Our findings indicate that this biparatopic ADC has promising potential as an effective therapy for metastatic breast cancer and a broader patient population may benefit from this unique HER2-targeting ADC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ado-Trastuzumab Emtansine
  • Animals
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Antineoplastic Agents / therapeutic use*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / immunology
  • Female
  • Humans
  • Immunotoxins / therapeutic use*
  • Maytansine / analogs & derivatives*
  • Maytansine / therapeutic use
  • Mice
  • Receptor, ErbB-2 / immunology*
  • Trastuzumab / therapeutic use*
  • Treatment Outcome


  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents
  • Immunotoxins
  • Maytansine
  • Receptor, ErbB-2
  • Trastuzumab
  • Ado-Trastuzumab Emtansine