6 research outputs found
Fragment-Based Approach to the Development of an Orally Bioavailable Lactam Inhibitor of Lipoprotein-Associated Phospholipase A2 (Lp-PLA<sub>2</sub>)
Lp-PLA<sub>2</sub> has been explored as a target for a number of
inflammation associated diseases, including cardiovascular disease
and dementia. This article describes the discovery of a new fragment
derived chemotype that interacts with the active site of Lp-PLA<sub>2</sub>. The starting fragment hit was discovered through an X-ray
fragment screen and showed no activity in the bioassay (IC<sub>50</sub> > 1 mM). The fragment hit was optimized using a variety of structure-based
drug design techniques, including virtual screening, fragment merging,
and improvement of shape complementarity. A novel series of Lp-PLA<sub>2</sub> inhibitors was generated with low lipophilicity and a promising
pharmacokinetic profile
Exploitation of a Novel Binding Pocket in Human Lipoprotein-Associated Phospholipase A2 (Lp-PLA<sub>2</sub>) Discovered through X‑ray Fragment Screening
Elevated levels of
human lipoprotein-associated phospholipase A2
(Lp-PLA<sub>2</sub>) are associated with cardiovascular disease and
dementia. A fragment screen was conducted against Lp-PLA<sub>2</sub> in order to identify novel inhibitors. Multiple fragment hits were
observed in different regions of the active site, including some hits
that bound in a pocket created by movement of a protein side chain
(approximately 13 Å from the catalytic residue Ser273). Using
structure guided design, we optimized a fragment that bound in this
pocket to generate a novel low nanomolar chemotype, which did not
interact with the catalytic residues
Exploitation of a Novel Binding Pocket in Human Lipoprotein-Associated Phospholipase A2 (Lp-PLA<sub>2</sub>) Discovered through X‑ray Fragment Screening
Elevated levels of
human lipoprotein-associated phospholipase A2
(Lp-PLA<sub>2</sub>) are associated with cardiovascular disease and
dementia. A fragment screen was conducted against Lp-PLA<sub>2</sub> in order to identify novel inhibitors. Multiple fragment hits were
observed in different regions of the active site, including some hits
that bound in a pocket created by movement of a protein side chain
(approximately 13 Å from the catalytic residue Ser273). Using
structure guided design, we optimized a fragment that bound in this
pocket to generate a novel low nanomolar chemotype, which did not
interact with the catalytic residues
Fragment-Based Discovery of 7-Azabenzimidazoles as Potent, Highly Selective, and Orally Active CDK4/6 Inhibitors
Herein, we describe the discovery of potent and highly
selective
inhibitors of both CDK4 and CDK6 via structure-guided optimization
of a fragment-based screening hit. CDK6 X-ray crystallography and
pharmacokinetic data steered efforts in identifying compound <b>6</b>, which showed >1000-fold selectivity for CDK4 over
CDKs 1 and 2 in an enzymatic assay. Furthermore, <b>6</b> demonstrated
in vivo inhibition of pRb-phosphorylation and oral efficacy in a Jeko-1
mouse xenograft model
Fragment-Based Discovery of a Potent, Orally Bioavailable Inhibitor That Modulates the Phosphorylation and Catalytic Activity of ERK1/2
Aberrant activation of the MAPK pathway
drives cell proliferation
in multiple cancers. Inhibitors of BRAF and MEK kinases are approved
for the treatment of BRAF mutant melanoma, but resistance frequently
emerges, often mediated by increased signaling through ERK1/2. Here,
we describe the fragment-based generation of ERK1/2 inhibitors that
block catalytic phosphorylation of downstream substrates such as RSK
but also modulate phosphorylation of ERK1/2 by MEK without directly
inhibiting MEK. X-ray crystallographic and biophysical fragment screening
followed by structure-guided optimization and growth from the hinge
into a pocket proximal to the C-α helix afforded highly potent
ERK1/2 inhibitors with excellent kinome selectivity. In BRAF mutant
cells, the lead compound suppresses pRSK and pERK levels and inhibits
proliferation at low nanomolar concentrations. The lead exhibits tumor
regression upon oral dosing in BRAF mutant xenograft models, providing
a promising basis for further optimization toward clinical pERK1/2
modulating ERK1/2 inhibitors
Fragment-Based Discovery of a Potent, Orally Bioavailable Inhibitor That Modulates the Phosphorylation and Catalytic Activity of ERK1/2
Aberrant activation of the MAPK pathway
drives cell proliferation
in multiple cancers. Inhibitors of BRAF and MEK kinases are approved
for the treatment of BRAF mutant melanoma, but resistance frequently
emerges, often mediated by increased signaling through ERK1/2. Here,
we describe the fragment-based generation of ERK1/2 inhibitors that
block catalytic phosphorylation of downstream substrates such as RSK
but also modulate phosphorylation of ERK1/2 by MEK without directly
inhibiting MEK. X-ray crystallographic and biophysical fragment screening
followed by structure-guided optimization and growth from the hinge
into a pocket proximal to the C-α helix afforded highly potent
ERK1/2 inhibitors with excellent kinome selectivity. In BRAF mutant
cells, the lead compound suppresses pRSK and pERK levels and inhibits
proliferation at low nanomolar concentrations. The lead exhibits tumor
regression upon oral dosing in BRAF mutant xenograft models, providing
a promising basis for further optimization toward clinical pERK1/2
modulating ERK1/2 inhibitors