4 research outputs found
A Fragment-Derived Clinical Candidate for Antagonism of XâLinked and Cellular Inhibitor of Apoptosis Proteins: 1â(6-[(4-Fluorophenyl)methyl]-5-(hydroxymethyl)-3,3-dimethylâ1<i>H</i>,2<i>H</i>,3<i>H</i>âpyrrolo[3,2â<i>b</i>]pyridin-1-yl)-2-[(2<i>R</i>,5<i>R</i>)â5-methyl-2-([(3R)-3-methylmorpholin-4-yl]methyl)piperazin-1-yl]ethan-1-one (ASTX660)
Inhibitor of apoptosis
proteins (IAPs) are promising anticancer
targets, given their roles in the evasion of apoptosis. Several peptidomimetic
IAP antagonists, with inherent selectivity for cellular IAP (cIAP)
over X-linked IAP (XIAP), have been tested in the clinic. A fragment
screening approach followed by structure-based optimization has previously
been reported that resulted in a low-nanomolar cIAP1 and XIAP antagonist
lead molecule with a more balanced cIAPâXIAP profile. We now
report the further structure-guided optimization of the lead, with
a view to improving the metabolic stability and cardiac safety profile,
to give the nonpeptidomimetic antagonist clinical candidate <b>27</b> (ASTX660), currently being tested in a phase 1/2 clinical
trial (NCT02503423)
A Fragment-Derived Clinical Candidate for Antagonism of XâLinked and Cellular Inhibitor of Apoptosis Proteins: 1â(6-[(4-Fluorophenyl)methyl]-5-(hydroxymethyl)-3,3-dimethylâ1<i>H</i>,2<i>H</i>,3<i>H</i>âpyrrolo[3,2â<i>b</i>]pyridin-1-yl)-2-[(2<i>R</i>,5<i>R</i>)â5-methyl-2-([(3R)-3-methylmorpholin-4-yl]methyl)piperazin-1-yl]ethan-1-one (ASTX660)
Inhibitor of apoptosis
proteins (IAPs) are promising anticancer
targets, given their roles in the evasion of apoptosis. Several peptidomimetic
IAP antagonists, with inherent selectivity for cellular IAP (cIAP)
over X-linked IAP (XIAP), have been tested in the clinic. A fragment
screening approach followed by structure-based optimization has previously
been reported that resulted in a low-nanomolar cIAP1 and XIAP antagonist
lead molecule with a more balanced cIAPâXIAP profile. We now
report the further structure-guided optimization of the lead, with
a view to improving the metabolic stability and cardiac safety profile,
to give the nonpeptidomimetic antagonist clinical candidate <b>27</b> (ASTX660), currently being tested in a phase 1/2 clinical
trial (NCT02503423)
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