Optimization of 1,4-Oxazine β-Secretase 1 (BACE1) Inhibitors Toward a Clinical Candidate

J Med Chem. 2018 Jun 28;61(12):5292-5303. doi: 10.1021/acs.jmedchem.8b00304. Epub 2018 Jun 11.

Abstract

In previous studies, the introduction of electron withdrawing groups to 1,4-oxazine BACE1 inhibitors reduced the p Ka of the amidine group, resulting in compound 2 that showed excellent in vivo efficacy, lowering Aβ levels in brain and CSF. However, a suboptimal cardiovascular safety margin, based on QTc prolongation, prevented further progression. Further optimization resulted in the replacement of the 2-fluoro substituent by a CF3-group, which reduced hERG inhibition. This has led to compound 3, with an improved cardiovascular safety margin and sufficiently safe in GLP toxicity studies to progress into clinical trials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravenous
  • Administration, Oral
  • Amyloid Precursor Protein Secretases / antagonists & inhibitors*
  • Amyloid Precursor Protein Secretases / metabolism
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Animals
  • Aspartic Acid Endopeptidases / antagonists & inhibitors*
  • Aspartic Acid Endopeptidases / metabolism
  • Biological Availability
  • Cardiovascular Diseases / chemically induced
  • Chemical and Drug Induced Liver Injury / etiology
  • Dogs
  • Drug Evaluation, Preclinical / methods
  • Drug Stability
  • ERG1 Potassium Channel / metabolism
  • Guinea Pigs
  • Humans
  • Male
  • Mice, Inbred Strains
  • Oxazines / chemistry
  • Peptide Fragments / cerebrospinal fluid
  • Protease Inhibitors / administration & dosage
  • Protease Inhibitors / adverse effects
  • Protease Inhibitors / chemistry*
  • Protease Inhibitors / pharmacology*
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship

Substances

  • Amyloid beta-Peptides
  • ERG1 Potassium Channel
  • KCNH2 protein, human
  • Oxazines
  • Peptide Fragments
  • Protease Inhibitors
  • amyloid beta-protein (1-42)
  • Amyloid Precursor Protein Secretases
  • Aspartic Acid Endopeptidases
  • BACE1 protein, human