7 research outputs found
Minor Structural Change to Tertiary Sulfonamide RORc Ligands Led to Opposite Mechanisms of Action
A minor structural change to tertiary
sulfonamide RORc ligands
led to distinct mechanisms of action. Co-crystal structures of two
compounds revealed mechanistically consistent protein conformational
changes. Optimized phenylsulfonamides were identified as RORc agonists
while benzylsulfonamides exhibited potent inverse agonist activity.
Compounds behaving as agonists in our biochemical assay also gave
rise to an increased production of IL-17 in human PBMCs whereas inverse
agonists led to significant suppression of IL-17 under the same assay
conditions. The most potent inverse agonist compound showed >180-fold
selectivity over the ROR isoforms as well as all other nuclear receptors
that were profiled
A Unique Approach to Design Potent and Selective Cyclic Adenosine Monophosphate Response Element Binding Protein, Binding Protein (CBP) Inhibitors
The
epigenetic regulator CBP/P300 presents a novel therapeutic
target for oncology. Previously, we disclosed the development of potent
and selective CBP bromodomain inhibitors by first identifying pharmacophores
that bind the KAc region and then building into the LPF shelf. Herein,
we report the “hybridization” of a variety of KAc-binding
fragments with a tetrahydroquinoline scaffold that makes optimal interactions
with the LPF shelf, imparting enhanced potency and selectivity to
the hybridized ligand. To demonstrate the utility of our hybridization
approach, two analogues containing unique Asn binders and the optimized
tetrahydroquinoline moiety were rapidly optimized to yield single-digit
nanomolar inhibitors of CBP with exquisite selectivity over BRD4(1)
and the broader bromodomain family
GNE-781, A Highly Advanced Potent and Selective Bromodomain Inhibitor of Cyclic Adenosine Monophosphate Response Element Binding Protein, Binding Protein (CBP)
Inhibition of the bromodomain of
the transcriptional regulator
CBP/P300 is an especially interesting new therapeutic approach in
oncology. We recently disclosed in vivo chemical tool <b>1</b> (GNE-272) for the bromodomain of CBP that was moderately potent
and selective over BRD4(1). In pursuit of a more potent and selective
CBP inhibitor, we used structure-based design. Constraining the aniline
of <b>1</b> into a tetrahydroquinoline motif maintained potency
and increased selectivity 2-fold. Structure–activity relationship
studies coupled with further structure-based design targeting the
LPF shelf, BC loop, and KAc regions allowed us to significantly increase
potency and selectivity, resulting in the identification of non-CNS
penetrant <b>19</b> (GNE-781, TR-FRET IC<sub>50</sub> = 0.94
nM, BRET IC<sub>50</sub> = 6.2 nM; BRD4(1) IC<sub>50</sub> = 5100
nΜ) that maintained good in vivo PK properties in multiple species.
Compound <b>19</b> displays antitumor activity in an AML tumor
model and was also shown to decrease Foxp3 transcript levels in a
dose dependent manner
Discovery of a Potent and Selective in Vivo Probe (GNE-272) for the Bromodomains of CBP/EP300
The single bromodomain of the closely
related transcriptional regulators
CBP/EP300 is a target of much recent interest in cancer and immune
system regulation. A co-crystal structure of a ligand-efficient screening
hit and the CBP bromodomain guided initial design targeting the LPF
shelf, ZA loop, and acetylated lysine binding regions. Structure–activity
relationship studies allowed us to identify a more potent analogue.
Optimization of permeability and microsomal stability and subsequent
improvement of mouse hepatocyte stability afforded <b>59</b> (GNE-272, TR-FRET IC<sub>50</sub> = 0.02 μM, BRET IC<sub>50</sub> = 0.41 μM, BRD4(1) IC<sub>50</sub> = 13 μM) that retained
the best balance of cell potency, selectivity, and in vivo PK. Compound <b>59</b> showed a marked antiproliferative effect in hematologic
cancer cell lines and modulates <i>MYC</i> expression in
vivo that corresponds with antitumor activity in an AML tumor model