7 research outputs found
Lipid Tales: Optimizing Arylomycin Membrane Anchors
Multidrug-resistant bacteria are spreading at alarming
rates, and
despite extensive efforts, no new antibiotic class with activity against
Gram-negative bacteria has been approved in over 50 years. LepB inhibitors
(LepBi) based on the arylomycin class of natural products are a novel
class of antibiotics and function by inhibiting the bacterial type
I signal peptidase (SPase) in Gram-negative bacteria. One critical
aspect of LepBi development involves optimization of the membrane-anchored
lipophilic portion of the molecule. We therefore developed an approach
that assesses the effect of this portion on the complicated equilibria
of plasma protein binding, crossing the outer membrane of Gram-negative
bacteria and anchoring in the bacterial inner membrane to facilitate
SPase binding. Our findings provide important insights into the development
of antibacterial agents where the target is associated with the inner
membrane of Gram-negative bacteria
Discovery of Highly Potent, Selective, and Efficacious Small Molecule Inhibitors of ERK1/2
Using
structure-based design, a novel series of pyridone ERK1/2
inhibitors was developed. Optimization led to the identification of
(<i>S</i>)-<b>14k</b>, a potent, selective, and orally
bioavailable agent that inhibited tumor growth in mouse xenograft
models. On the basis of its in vivo efficacy and preliminary safety
profiles, (<i>S</i>)-<b>14k</b> was selected for further
preclinical evaluation
GluN2A-Selective Pyridopyrimidinone Series of NMDAR Positive Allosteric Modulators with an Improved <i>in Vivo</i> Profile
The <i>N</i>-methyl-d-aspartate receptor (NMDAR)
is an ionotropic glutamate receptor, gated by the endogenous coagonists
glutamate and glycine, permeable to Ca<sup>2+</sup> and Na<sup>+</sup>. NMDAR dysfunction is associated with numerous neurological and
psychiatric disorders, including schizophrenia, depression, and Alzheimer’s
disease. Recently, we have disclosed GNE-0723 (<b>1</b>), a
GluN2A subunit-selective and brain-penetrant positive allosteric modulator
(PAM) of NMDARs. This work highlights the discovery of a related pyridopyrimidinone
core with distinct structure–activity relationships, despite
the structural similarity to GNE-0723. GNE-5729 (<b>13</b>),
a pyridopyrimidinone-based NMDAR PAM, was identified with both an
improved pharmacokinetic profile and increased selectivity against
AMPARs. We also include X-ray structure analysis and modeling to propose
hypotheses for the activity and selectivity differences
Discovery of (<i>S</i>)‑1-(1-(4-Chloro-3-fluorophenyl)-2-hydroxyethyl)-4-(2-((1-methyl‑1<i>H</i>‑pyrazol-5-yl)amino)pyrimidin-4-yl)pyridin-2(1<i>H</i>)‑one (GDC-0994), an Extracellular Signal-Regulated Kinase 1/2 (ERK1/2) Inhibitor in Early Clinical Development
The extracellular
signal-regulated kinases ERK1/2 represent an
essential node within the RAS/RAF/MEK/ERK signaling cascade that is
commonly activated by oncogenic mutations in BRAF or RAS or by upstream
oncogenic signaling. While targeting upstream nodes with RAF and MEK
inhibitors has proven effective clinically, resistance frequently
develops through reactivation of the pathway. Simultaneous targeting
of multiple nodes in the pathway, such as MEK and ERK, offers the
prospect of enhanced efficacy as well as reduced potential for acquired
resistance. Described herein is the discovery and characterization
of GDC-0994 (<b>22</b>), an orally bioavailable small molecule
inhibitor selective for ERK kinase activity
Discovery of GluN2A-Selective NMDA Receptor Positive Allosteric Modulators (PAMs): Tuning Deactivation Kinetics via Structure-Based Design
The <i>N</i>-methyl-d-aspartate receptor (NMDAR)
is a Na<sup>+</sup> and Ca<sup>2+</sup> permeable ionotropic glutamate
receptor that is activated by the coagonists glycine and glutamate.
NMDARs are critical to synaptic signaling and plasticity, and their
dysfunction has been implicated in a number of neurological disorders,
including schizophrenia, depression, and Alzheimer’s disease.
Herein we describe the discovery of potent GluN2A-selective NMDAR
positive allosteric modulators (PAMs) starting from a high-throughput
screening hit. Using structure-based design, we sought to increase
potency at the GluN2A subtype, while improving selectivity against
related α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
receptors (AMPARs). The structure–activity relationship of
channel deactivation kinetics was studied using a combination of electrophysiology
and protein crystallography. Effective incorporation of these strategies
resulted in the discovery of GNE-0723 (<b>46</b>), a highly
potent and brain penetrant GluN2A-selective NMDAR PAM suitable for <i>in vivo</i> characterization
Potent GCN2 Inhibitor Capable of Reversing MDSC-Driven T Cell Suppression Demonstrates In Vivo Efficacy as a Single Agent and in Combination with Anti-Angiogenesis Therapy
General
control nonderepressible 2 (GCN2) protein kinase is a cellular
stress sensor within the tumor microenvironment (TME), whose signaling
cascade has been proposed to contribute to immune escape in tumors.
Herein, we report the discovery of cell-potent GCN2 inhibitors with
excellent selectivity against its closely related Integrated Stress
Response (ISR) family members heme-regulated inhibitor kinase (HRI),
protein kinase R (PKR), and (PKR)-like endoplasmic reticulum kinase
(PERK), as well as good kinome-wide selectivity and favorable PK.
In mice, compound 39 engages GCN2 at levels ≥80%
with an oral dose of 15 mg/kg BID. We also demonstrate the ability
of compound 39 to alleviate MDSC-related T cell suppression
and restore T cell proliferation, similar to the effect seen in MDSCs
from GCN2 knockout mice. In the LL2 syngeneic mouse model, compound 39 demonstrates significant tumor growth inhibition (TGI)
as a single agent. Furthermore, TGI mediated by anti-VEGFR was enhanced
by treatment with compound 39 demonstrating the complementarity
of these two mechanisms
Potent GCN2 Inhibitor Capable of Reversing MDSC-Driven T Cell Suppression Demonstrates In Vivo Efficacy as a Single Agent and in Combination with Anti-Angiogenesis Therapy
General
control nonderepressible 2 (GCN2) protein kinase is a cellular
stress sensor within the tumor microenvironment (TME), whose signaling
cascade has been proposed to contribute to immune escape in tumors.
Herein, we report the discovery of cell-potent GCN2 inhibitors with
excellent selectivity against its closely related Integrated Stress
Response (ISR) family members heme-regulated inhibitor kinase (HRI),
protein kinase R (PKR), and (PKR)-like endoplasmic reticulum kinase
(PERK), as well as good kinome-wide selectivity and favorable PK.
In mice, compound 39 engages GCN2 at levels ≥80%
with an oral dose of 15 mg/kg BID. We also demonstrate the ability
of compound 39 to alleviate MDSC-related T cell suppression
and restore T cell proliferation, similar to the effect seen in MDSCs
from GCN2 knockout mice. In the LL2 syngeneic mouse model, compound 39 demonstrates significant tumor growth inhibition (TGI)
as a single agent. Furthermore, TGI mediated by anti-VEGFR was enhanced
by treatment with compound 39 demonstrating the complementarity
of these two mechanisms