Mechanistic Investigations of Diarrhea Toxicity Induced by Anti-HER2/3 Combination Therapy

Mol Cancer Ther. 2018 Jul;17(7):1464-1474. doi: 10.1158/1535-7163.MCT-17-1268. Epub 2018 Apr 13.


Combination of targeted therapies is expected to provide superior efficacy in the treatment of cancer either by enhanced antitumor activity or by preventing or delaying the development of resistance. Common challenges in developing combination therapies include the potential of additive and aggravated toxicities associated with pharmacologically related adverse effects. We have recently reported that combination of anti-HER2 and anti-HER3 antibodies, pertuzumab and lumretuzumab, along with paclitaxel chemotherapy in metastatic breast cancer, resulted in a high incidence of diarrhea that ultimately limited further clinical development of this combination. Here, we further dissected the diarrhea profile of the various patient dose cohorts and carried out in vitro investigations in human colon cell lines and explants to decipher the contribution and the mechanism of anti-HER2/3 therapeutic antibodies to intestinal epithelium malfunction. Our clinical investigations in patients revealed that while dose reduction of lumretuzumab, omission of pertuzumab loading dose, and introduction of a prophylactic antidiarrheal treatment reduced most severe adverse events, patients still suffered from persistent diarrhea during the treatment. Our in vitro investigations showed that pertuzumab and lumretuzumab combination treatment resulted in upregulation of chloride channel activity without indication of intestinal barrier disruption. Overall, our findings provide a mechanistic rationale to explore alternative of conventional antigut motility using medication targeting chloride channel activity to mitigate diarrhea of HER combination therapies. Mol Cancer Ther; 17(7); 1464-74. ©2018 AACR.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Anti-Idiotypic / administration & dosage*
  • Antibodies, Anti-Idiotypic / adverse effects
  • Antibodies, Monoclonal, Humanized / administration & dosage
  • Antibodies, Monoclonal, Humanized / adverse effects
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage
  • Antineoplastic Combined Chemotherapy Protocols / adverse effects
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology
  • Caco-2 Cells
  • Cell Proliferation / drug effects
  • Colonic Neoplasms / drug therapy*
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / pathology
  • Combined Modality Therapy
  • Diarrhea / chemically induced
  • Diarrhea / genetics*
  • Diarrhea / pathology
  • Dose-Response Relationship, Drug
  • Drug-Related Side Effects and Adverse Reactions / drug therapy
  • Drug-Related Side Effects and Adverse Reactions / pathology
  • Female
  • Humans
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / pathology
  • Middle Aged
  • Neoplasm Metastasis
  • Paclitaxel / administration & dosage
  • Paclitaxel / adverse effects
  • Receptor, ErbB-2 / antagonists & inhibitors
  • Receptor, ErbB-2 / genetics*
  • Receptor, ErbB-3 / antagonists & inhibitors
  • Receptor, ErbB-3 / genetics*


  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal, Humanized
  • ERBB2 protein, human
  • ERBB3 protein, human
  • Receptor, ErbB-2
  • Receptor, ErbB-3
  • pertuzumab
  • Paclitaxel
  • lumretuzumab