3 research outputs found
Optimization of Fused Bicyclic Allosteric SHP2 Inhibitors
SHP2 is a nonreceptor protein tyrosine phosphatase within the mitogen-activated protein kinase (MAPK) pathway controlling cell growth, differentiation, and oncogenic transformation. SHP2 also participates in the programed cell death pathway (PD-1/PD-L1) governing immune surveillance. Small-molecule inhibition of SHP2 has been widely investigated, including in our previous reports describing SHP099 (2), which binds to a tunnel-like allosteric binding site. To broaden our approach to allosteric inhibition of SHP2, we conducted additional hit finding, evaluation, and structure-based scaffold morphing. These studies, reported here in the first of two papers, led to the identification of multiple 5,6-fused bicyclic scaffolds that bind to the same allosteric tunnel as 2. We demonstrate the structural diversity permitted by the tunnel pharmacophore and culminated in the identification of pyrazolopyrimidinones (e.g., SHP389, 1) that modulate MAPK signaling in vivo. These studies also served as the basis for further scaffold morphing and optimization, detailed in the following manuscript
6-Amino-3-methylpyrimidinones as Potent, Selective, and Orally Efficacious SHP2 Inhibitors
Protein tyrosine phosphatase SHP2 is an oncoprotein associated with cancer as well as a potential immune modulator because of its role in the programmed cell death PD-L1/PD-1 pathway. In the preceding manuscript, we described the optimization of a fused, bicyclic screening hit for potency, selectivity, and physicochemical properties in order to further expand the chemical diversity of allosteric SHP2 inhibitors. In this manuscript, we describe the further expansion of our approach, morphing the fused, bicyclic system into a novel monocyclic pyrimidinone scaffold through our understanding of SAR and use of structure-based design. These studies led to the identification of SHP394 (1), an orally efficacious inhibitor of SHP2, with high lipophilic efficiency, improved potency, and enhanced pharmacokinetic properties. We also report other pyrimidinone analogues with favorable pharmacokinetic and potency profiles. Overall, this work improves upon our previously described allosteric inhibitors and exemplifies and extends the range of permissible chemical templates that inhibit SHP2 via the allosteric mechanism
Allosteric Inhibition of SHP2: Identification of a Potent, Selective, and Orally Efficacious Phosphatase Inhibitor
SHP2
is a nonreceptor protein tyrosine phosphatase (PTP) encoded by the <i>PTPN11</i> gene involved in cell growth and differentiation
via the MAPK signaling pathway. SHP2 also purportedly plays an important
role in the programmed cell death pathway (PD-1/PD-L1). Because it
is an oncoprotein associated with multiple cancer-related diseases,
as well as a potential immunomodulator, controlling SHP2 activity
is of significant therapeutic interest. Recently in our laboratories,
a small molecule inhibitor of SHP2 was identified as an allosteric
modulator that stabilizes the autoinhibited conformation of SHP2.
A high throughput screen was performed to identify progressable chemical
matter, and X-ray crystallography revealed the location of binding
in a previously undisclosed allosteric binding pocket. Structure-based
drug design was employed to optimize for SHP2 inhibition, and several
new protein–ligand interactions were characterized. These studies
culminated in the discovery of 6-(4-amino-4-methylpiperidin-1-yl)-3-(2,3-dichlorophenyl)Âpyrazin-2-amine
(SHP099, <b>1</b>), a potent, selective, orally bioavailable,
and efficacious SHP2 inhibitor