NGP 555, a γ-secretase modulator, shows a beneficial shift in the ratio of amyloid biomarkers in human cerebrospinal fluid at safe doses

INTRODUCTION

Currently, there is no cure for Alzheimer's disease (AD), and it is widely accepted that AD is a complex disease with multiple approaches necessary to prevent and treat the disease.

METHODS

Using amyloid biomarkers in human cerebrospinal fluid, pharmacokinetic, safety, and metabolism studies, we investigate the properties of NGP 555, γ-secretase modulator, for the first time in human clinical trials.

RESULTS

Our preclinical and clinical studies combined show beneficial effects with NGP 555 on synaptic response and amyloid cerebrospinal fluid biomarkers while avoiding negative side effects. Importantly, pharmacokinetic and pharmacodynamic parameters combined with safety outcomes indicate that NGP 555 penetrates the blood-brain barrier and increases the ratio of amyloid-β peptide Aβ37 and Aβ38 compared with that of Aβ42, establishing a proof of target engagement in humans in a 14 day, once-daily oral dosing trial.

DISCUSSION

In humans, NGP 555 has demonstrated a beneficial shift in the production of Aβ37 and Aβ38 versus Aβ42 biomarker levels in the cerebrospinal fluid while maintaining an adequate safety profile. The overall clinical goal is to achieve an optimal balance of efficacy for altering amyloid-β peptide (Aβ) biomarkers while maintaining a safe profile so that NGP 555 can be given early in AD to prevent production of Aβ42 and accumulation of amyloid plaques, in an effort to prevent aggregation of tau and destruction of neurons and synapses resulting in cognitive decline.

NGP 555, a γ-Secretase Modulator, Lowers the Amyloid Biomarker, Aβ42, in Cerebrospinal Fluid while Preventing Alzheimer's Disease Cognitive Decline in Rodents

Introduction

Alzheimer's disease (AD) is defined by the progressive accumulation of amyloid plaques and neurofibrillary tangles in the brain which precedes cognitive decline by years.

Methods

Using amyloid biomarkers, chemical modeling, mouse behavioral models, and drug development techniques, we investigate the properties of NGP 555, a clinical-stage γ-secretase modulator.

Results

NGP 555 shifts amyloid peptide production to the smaller, nonaggregating forms of amyloid. Our preclinical studies show beneficial effects on amyloid biomarkers, pathology, and cognition. NGP 555 has successfully completed chemistry, pharmacology, toxicity, metabolism, and safety studies.

Discussion

Abundant data support Aβ₄₂ as a target for prophylactic or early-stage intervention therapies in AD. The γ-secretase modulator, NGP 555 is being actively developed in human clinical trials for the prevention of Alzheimer's disease with the overall aim to achieve an appropriate balance of potency/efficacy on reducing the toxic forms of amyloid versus safety.

Modulation of gamma-secretase reduces beta-amyloid deposition in a transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is characterized pathologically by the abundance of senile plaques and neurofibrillary tangles in the brain. We synthesized over 1200 novel gamma-secretase modulator (GSM) compounds that reduced Abeta(42) levels without inhibiting epsilon-site cleavage of APP and Notch, the generation of the APP and Notch intracellular domains, respectively. These compounds also reduced Abeta(40) levels while concomitantly elevating levels of Abeta(38) and Abeta(37). Immobilization of a potent GSM onto an agarose matrix quantitatively recovered Pen-2 and to a lesser degree PS-1 NTFs from cellular extracts. Moreover, oral administration (once daily) of another potent GSM to Tg 2576 transgenic AD mice displayed dose-responsive lowering of plasma and brain Abeta(42); chronic daily administration led to significant reductions in both diffuse and neuritic plaques. These effects were observed in the absence of Notch-related changes (e.g., intestinal proliferation of goblet cells), which are commonly associated with repeated exposure to functional gamma-secretase inhibitors (GSIs).

N-[[(Mercaptoacetyl)amino]benzoyl]glycines as mucolytic agents

m- and p-aminobenzoic acids were converted to the title compounds by sequential use of ClCH2COCl, SOCl2, glycine methyl or ethyl ester, AcSK, and hydrolysis. The title compounds and a number of salts were compared for mucolytic activity, toxicity, stability, and hygroscopicity. When compared to N-acetyl-L-cysteine (NAC), the compounds exhibit several times the in vitro mucolytic activity of NAC on a molar basis. The most promising candidate appears to be the sodium salt 3.5H2O 2 of the meta series.

Antihypertensive indole derivatives of phenoxypropanolamines with beta-adrenergic receptor antagonist and vasodilating activity

A series of 25 aryloxypropanolamines containing the 3-indolyl-tert-butyl [i.e., 1,1-dimethyl-2-(1H-indol-3-yl)ethyl] or substituted 3-indolyl-tert-butyl moiety as the N substituent is reported. These compounds have been tested for antihypertensive activity in spontaneously hypertensive rats (SHR), beta-adrenergic receptor antagonist action in conscious normotensive rats, vasodilating activity in ganglion-blocked rats with blood pressure maintained by angiotensin II infusion, and for intrinsic sympathomimetic action (ISA) in reserpinized rats. Some of the compounds exhibit antihypertensive activity in combination with beta adrenergic receptor antagonist and vasodilating action. The structure--activity relationships in these tests are discussed.

Adrenergic sulfonanilides. 4. Centrally active beta-adrenergic agonists

The central nervous system (CNS) activities of a number of soterenol analogs have been investigated, and several of these compounds possessed potent morphine antagonistic and anorexiant properties. The CNS activity of these compounds was enhanced by certain lipophilic [e.g., 1,1-dimethyl-2-phenethyl (43) or cyclopropyl (40 and 44)] nitrogen substituents; however, minor structural changes on either the aromatic or side-chain moieties drastically reduced central activity. Toxicity in this series was related to the inherent alpha-adrenergic stimulating component (direct or indirect).