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.
Harrie J M Gijsen  1 Sergio A Alonso de Diego  2 Michel De Cleyn  1 Aránzazu García-Molina  2 Gregor J Macdonald  1 Carolina Martínez-Lamenca  1 Daniel Oehlrich  1 Hana Prokopcova  1 Frederik J R Rombouts  1 Michel Surkyn  1 Andrés A Trabanco  2 Sven Van Brandt  1 Dries Van den Bossche  1 Michiel Van Gool  2 Nigel Austin  3 Herman Borghys  3 Deborah Dhuyvetter  3 Diederik Moechars  4
Affiliations
  • 1. Neuroscience Medicinal Chemistry, Janssen Research & Development , Janssen Pharmaceutica NV , Turnhoutseweg 30 , B-2340 Beerse , Belgium.
  • 2. Neuroscience Medicinal Chemistry, Janssen Research & Development , Janssen-Cilag SA , C/Jarama 75A , 45007 Toledo , Spain.
  • 3. Discovery Sciences, Janssen Research & Development , Janssen Pharmaceutica NV , Turnhoutseweg 30 , B-2340 Beerse , Belgium.
  • 4. Neuroscience Biology, Janssen Research & Development , Janssen Pharmaceutica NV , Turnhoutseweg 30 , B-2340 Beerse , Belgium.
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.

Products