Zihao Hua

Development of Novel Dual Binders as Potent, Selective, and Orally Bioavailable Tankyrase Inhibitors

Tankyrases (TNKS1 and TNKS2) are proteins in the poly ADP-ribose polymerase (PARP) family. They have been shown to directly bind to axin proteins, which negatively regulate the Wnt pathway by promoting β-catenin degradation. Inhibition of tankyrases may offer a novel approach to the treatment of APC-mutant colorectal cancer. Hit compound 8 was identified as an inhibitor of tankyrases through a combination of substructure searching of the Amgen compound collection based on a minimal binding pharmacophore hypothesis and high-throughput screening. Herein we report the structure- and property-based optimization of compound 8 leading to the identification of more potent and selective tankyrase inhibitors 22 and 49 with improved pharmacokinetic properties in rodents, which are well suited as tool compounds for further in vivo validation studies.

2-Phenylamino-6-cyano-1H-benzimidazole-based isoform selective casein kinase 1 gamma (CK1γ) inhibitors

Screening of the Amgen compound library led to the identification of 2-phenylamino-6-cyano-1H-benzimidazole 1a as a potent CK1 gamma inhibitor with excellent kinase selectivity and unprecedented CK1 isoform selectivity. Further structure-based optimization of this series resulted in the discovery of 1h which possessed good enzymatic and cellular potency, excellent CK1 isoform and kinase selectivity, and acceptable pharmacokinetic properties.

Structure-Based Design of Potent and Selective CK1γ Inhibitors.

Aberrant activation of the Wnt pathway is believed to drive the development and growth of some cancers. The central role of CK1γ in Wnt signal transduction makes it an attractive target for the treatment of Wnt-pathway dependent cancers. We describe a structure-based approach that led to the discovery of a series of pyridyl pyrrolopyridinones as potent and selective CK1γ inhibitors. These compounds exhibited good enzyme and cell potency, as well as selectivity against other CK1 isoforms. A single oral dose of compound 13 resulted in significant inhibition of LRP6 phosphorylation in a mouse tumor PD model.

Abstract 1621: Discovery of pyridyl pyrrolopyridinones as potent and selective CK1γ inhibitors

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA The canonical Wnt pathway regulates the ability of β-catenin to activate specific target genes. Aberrant activation of the Wnt pathway is believed to drive the development and growth of many cancers; for example, APC mutations were observed in >80% of the sporadic colorectal cancers. The casein kinase 1 (CK1) family of serine/threonine protein kinases is highly conserved. Multiple members of the CK1 family are shown to regulate the Wnt pathway through interactions with various proteins. The central role of CK1γ in Wnt signal transduction makes it an attractive target for the treatment of Wnt-pathway dependent cancers. We employed a structure-based approach and identified a series of pyridyl pyrrolopyridinones as potent and selective CK1γ inhibitors. These compounds exhibited good enzyme and cell potency, as well as selectivity against other CK1 isoforms, and favorable rodent PK profiles. Oral dosing of optimized lead compounds resulted in significant inhibition of LRP6 phosphorylation in a mouse tumor PD model. Citation Format: Hongbing Huang, Lisa Acquaviva, Howard Bregman, John Buchanan, Nagasree Chakka, Erin F. DiMauro, Jennifer Dovey, Hakan Gunaydin, Zihao Hua, Xin Huang, Liyue Huang, Vinod F. Patel, Matthew W. Martin, Randy Serafino, Cindy Wilson. Discovery of pyridyl pyrrolopyridinones as potent and selective CK1γ inhibitors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1621. doi:10.1158/1538-7445.AM2014-1621