Efficacy and tolerability of AFPep, a cyclic peptide with anti-breast cancer properties

Toxicol Appl Pharmacol. 2018 Apr 15:345:10-18. doi: 10.1016/j.taap.2018.03.004. Epub 2018 Mar 6.

Abstract

Purpose: The purpose of this study is to assess the efficacy and safety profile of AFPep, a 9-amino acid cyclic peptide prior to its entry into pre-clinical toxicology analyses en route to clinical trials.

Methods: AFPep was assessed for anti-estrogenic activity in a mouse uterine growth assay and for breast cancer therapeutic efficacy in a human tumor xenograft model in mice. AFPep was assessed for tolerability in a variety of in vivo models, notably including assessment for effects on rat liver and human hepatocellular carcinoma cell lines and xenografts.

Results: AFPep arrests the growth of human MCF-7 breast cancer xenografts, inhibits the estrogen-induced growth of mouse uteri, and does not affect liver growth nor stimulate growth of human hepatocellular carcinoma cell lines when growing in vitro or as xenografts in vivo. AFPep is well tolerated in mice, rats, dogs, and primates.

Conclusions: AFPep is effective for the treatment of ER-positive breast cancer and exhibits a therapeutic index that is substantially wider than that for drugs currently in clinical use. The data emphasize the importance of pursuing pre-clinical toxicology studies with the intent to enter clinical trials.

Keywords: Breast cancer; Efficacy; Hepatocellular carcinoma; Prevention; Therapeutics; Toxicity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Dogs
  • Estrogen Antagonists / pharmacology
  • Estrogen Antagonists / therapeutic use*
  • Female
  • Hep G2 Cells
  • Humans
  • MCF-7 Cells
  • Macaca mulatta
  • Mice
  • Mice, SCID
  • Peptide Fragments / pharmacology
  • Peptide Fragments / therapeutic use*
  • Peptides, Cyclic / pharmacology
  • Peptides, Cyclic / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Treatment Outcome
  • Tumor Burden / drug effects
  • Tumor Burden / physiology
  • Xenograft Model Antitumor Assays / methods
  • alpha-Fetoproteins / pharmacology
  • alpha-Fetoproteins / therapeutic use*

Substances

  • AFPep peptide
  • Estrogen Antagonists
  • Peptide Fragments
  • Peptides, Cyclic
  • alpha-Fetoproteins