ABSTRACT
The identification and in vitro and in vivo characterization of a potent SHI-1:2 are described. Kinetic analysis indicated that biaryl inhibitors exhibit slow binding kinetics in isolated HDAC1 and HDAC2 preparations. Delayed histone hyperacetylation and gene expression changes were also observed in cell culture, and histone acetylation was observed in vivo beyond disappearance of drug from plasma. In vivo studies further demonstrated that continuous target inhibition was well tolerated and efficacious in tumor-bearing mice, leading to tumor growth inhibition with either once-daily or intermittent administration.
ABSTRACT
The development of a novel series of purines as gamma-secretase modulators for potential use in the treatment of Alzheimer's disease is disclosed herein. Optimization of a previously disclosed pyrimidine series afforded a series of potent purine-based gamma-secretase modulators with 300- to 2000-fold in vitro selectivity over inhibition of Notch cleavage and that selectively reduces Alphabeta42 in an APP-YAC transgenic mouse model.
Subject(s)
Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Peptides/antagonists & inhibitors , Peptide Fragments/antagonists & inhibitors , Purines/chemistry , Purines/therapeutic use , Amyloid Precursor Protein Secretases/genetics , Amyloid beta-Peptides/metabolism , Animals , Humans , Mice , Mice, Transgenic , Peptide Fragments/metabolism , Purines/pharmacology , Receptors, Notch/metabolism , Structure-Activity RelationshipABSTRACT
We report herein a novel series of difluoropiperidine acetic acids as modulators of gamma-secretase. Synthesis of 2-aryl-3,3-difluoropiperidine analogs was facilitated by a unique and selective beta-difluorination with Selectfluor. Compounds 1f and 2c were selected for in vivo assessment and demonstrated selective lowering of Abeta42 in a genetically engineered mouse model of APP processing. Moreover, in a 7-day safety study, rats treated orally with compound 1f (250mg/kg per day, AUC(0-24)=2100microMh) did not exhibit Notch-related effects.
Subject(s)
Acetates/chemistry , Amyloid Precursor Protein Secretases/metabolism , Fluorine/chemistry , Piperidines/chemistry , Acetates/chemical synthesis , Acetates/pharmacokinetics , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Animals , Diazonium Compounds/chemistry , Disease Models, Animal , Mice , Mice, Transgenic , Peptide Fragments/genetics , Peptide Fragments/metabolism , Piperidines/chemical synthesis , Piperidines/pharmacokinetics , Rats , Receptors, Notch/metabolismABSTRACT
A potent family of spirocyclic nicotinyl aminobenzamide selective HDAC1/HDAC2 inhibitors (SHI-1:2) is profiled. The incorporation of a biaryl zinc-binding motif into a nicotinyl scaffold resulted in enhanced potency and selectivity versus HDAC3, but also imparted hERG activity. It was discovered that increasing polar surface area about the spirocycle attenuates this liability. Compound 12 induced a 4-fold increase in acetylated histone H2B in an HCT-116 xenograft model study with acute exposure, and inhibited tumor growth in a 21-day efficacy study with qd dosing.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Ether-A-Go-Go Potassium Channels/metabolism , Histone Deacetylase Inhibitors , Niacinamide/chemical synthesis , Niacinamide/pharmacology , Spiro Compounds/chemical synthesis , Spiro Compounds/pharmacology , Animals , Antineoplastic Agents/chemistry , Benzamides/chemical synthesis , Benzamides/chemistry , Benzamides/pharmacology , Combinatorial Chemistry Techniques , ERG1 Potassium Channel , Ether-A-Go-Go Potassium Channels/drug effects , HCT116 Cells , Histone Deacetylases , Histones/analysis , Humans , Mice , Mice, Nude , Molecular Structure , Niacinamide/chemistry , Protein Isoforms , Spiro Compounds/chemistry , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
We report herein the initial exploration of novel selective HDAC1/HDAC2 inhibitors (SHI-1:2). Optimized SHI-1:2 structures exhibit enhanced intrinsic activity against HDAC1 and HDAC2, and are greater than 100-fold selective versus other HDACs, including HDAC3. Based on the SAR of these agents and our current understanding of the HDAC active site, we postulate that the SHI-1:2 extend the existing HDAC inhibitor pharmacophore to include an internal binding domain.
Subject(s)
Benzene Derivatives/chemical synthesis , Benzene Derivatives/pharmacology , Histone Deacetylase Inhibitors , Models, Molecular , Benzene Derivatives/chemistry , Binding Sites/drug effects , Histone Deacetylase 1 , Histone Deacetylase 2 , Histone Deacetylases/chemistry , Histone Deacetylases/metabolism , Humans , Molecular Structure , Protein Isoforms , Repressor Proteins , Structure-Activity RelationshipABSTRACT
This communication highlights the development of a nicotinamide series of histone deacetylase inhibitors within the benzamide structural class. Extensive exploration around the nicotinamide core led to the discovery of a class I selective HDAC inhibitor that possesses excellent intrinsic and cell-based potency, acceptable ancillary pharmacology, favorable pharmacokinetics, sustained pharmacodynamics in vitro, and achieves in vivo efficacy in an HCT116 xenograft model.
