Discovery of Clinical Candidate PF-06648671: A Potent γ-Secretase Modulator for the Treatment of Alzheimer's Disease

J Med Chem. 2024 Jun 27;67(12):10248-10262. doi: 10.1021/acs.jmedchem.4c00580. Epub 2024 Jun 7.

Abstract

Herein, we describe the design and synthesis of γ-secretase modulator (GSM) clinical candidate PF-06648671 (22) for the treatment of Alzheimer's disease. A key component of the design involved a 2,5-cis-tetrahydrofuran (THF) linker to impart conformational rigidity and lock the compound into a putative bioactive conformation. This effort was guided using a pharmacophore model since crystallographic information was not available for the membrane-bound γ-secretase protein complex at the time of this work. PF-06648671 achieved excellent alignment of whole cell in vitro potency (Aβ42 IC50 = 9.8 nM) and absorption, distribution, metabolism, and excretion (ADME) parameters. This resulted in favorable in vivo pharmacokinetic (PK) profile in preclinical species, and PF-06648671 achieved a human PK profile suitable for once-a-day dosing. Furthermore, PF-06648671 was found to have favorable brain availability in rodent, which translated into excellent central exposure in human and robust reduction of amyloid β (Aβ) 42 in cerebrospinal fluid (CSF).

MeSH terms

  • Alzheimer Disease* / drug therapy
  • Amyloid Precursor Protein Secretases* / antagonists & inhibitors
  • Amyloid Precursor Protein Secretases* / metabolism
  • Amyloid beta-Peptides* / metabolism
  • Animals
  • Brain / metabolism
  • Drug Discovery
  • Furans / chemical synthesis
  • Furans / chemistry
  • Furans / pharmacokinetics
  • Furans / pharmacology
  • Furans / therapeutic use
  • Humans
  • Male
  • Mice
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship

Substances

  • Amyloid Precursor Protein Secretases
  • Amyloid beta-Peptides
  • Furans