Investigational phosphodiesterase inhibitors in phase I and phase II clinical trials for Alzheimer's disease

Jos Prickaerts*, Pim R A Heckman, Arjan Blokland

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

INTRODUCTION: Phosphodiesterase (PDE) inhibitors improve signaling pathways in brain circuits by increasing intracellular cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP). In the last decade, the first clinical studies investigating selective PDE inhibitors in Alzheimer's disease (AD) have been initiated, based on their positive effects on cognitive processes and neuroprotection in numerous animal studies. Areas covered: This article reviews the clinical studies investigating the pro-cognitive/neuroprotective effects of PDE inhibitors in patients with AD, as well as in age-associated memory impaired elderly and patients with mild cognitive impairment (MCI), the prodromal stage of AD. PDE inhibitors will also be discussed with respect to adverse effects including safety and tolerability. Expert opinion: The limited available data of clinical studies with PDE inhibitors tested in different populations of AD patients do not allow the drawing of any concrete conclusion yet. Currently, studies with a PDE3 (cilostazol) or PDE9 inhibitor (BI 409,306) are still ongoing in patients with MCI or AD, respectively. Studies with PDE4 inhibitors (HT-0712, roflumilast and BPN14770) in healthy elderly and elderly with age-associated memory impairments indicate that the optimum dose and/or inhibiting the most relevant PDE isoform hold great promise when tested in the appropriate population of patients with MCI or AD eventually.

Original languageEnglish
Pages (from-to)1033-1048
Number of pages16
JournalExpert Opinion on Investigational Drugs
Volume26
Issue number9
Early online date3 Aug 2017
DOIs
Publication statusPublished - 9 Aug 2017

Keywords

  • Journal Article
  • LONG-TERM-MEMORY
  • COGNITIVE PERFORMANCE
  • cognition
  • cGMP
  • IMPROVES MEMORY
  • cAMP
  • SYNAPTIC PLASTICITY
  • 10A INHIBITORS
  • PDE4D INHIBITORS
  • neuroprotection
  • MOUSE MODEL
  • DOUBLE-BLIND
  • mild cognitive impairment
  • phosphodiesterase
  • CEREBRAL-BLOOD-FLOW
  • Alzheimer's disease
  • ENHANCES MEMORY

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