3 research outputs found
Imidazo[1,2-<i>a</i>]pyridines That Directly Interact with Hepatitis C NS4B: Initial Preclinical Characterization
A series of imidazo[1,2-<i>a</i>]pyridines
which directly
bind to HCV Non-Structural Protein 4B (NS4B) is described. This series
demonstrates potent <i>in vitro</i> inhibition of HCV replication
(EC<sub>50</sub> < 10 nM), direct binding to purified NS4B protein
(IC<sub>50</sub> < 20 nM), and an HCV resistance pattern associated
with NS4B (H94N/R, V105L/M, F98L) that are unique among reported HCV
clinical assets, suggestive of the potential for additive or synergistic
combination with other small molecule inhibitors of HCV replication
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