Exploration of macrocyclic peptide binders to the extracellular CRD domain of human receptor tyrosine kinase-like orphan receptor 1 (ROR1).

Elevated levels of receptor tyrosine kinase-like orphan receptor 1 (RORl) expression are observed in multiple hematological and solid tumors, but not in most of the healthy adult tissues, identifying ROR1 as an attractive target for tumor-specific therapy. Herein we will describe the discovery of macrocyclic peptides as binders of the extracellular Cysteine-Rich Domain (CRD) of human ROR1 via mRNA in vitro selection technology using the PDPS platform, followed by exploration of sidechain SAR of parent macrocycle peptides, fluorescently labeled analogs, and a Peptide Drug Conjugate (PDC). The parent macrocyclic peptides represented by Compound 1 and Compound 14 displayed nanomolar cell-based binding to ROR1 and relatively good internalization in 786-O and MDA-MB-231 tumor cell lines. However, these peptides were not observed to induce apoptosis in Mia PaCa-2 cells, a model pancreatic tumor cell line with a relatively low level of cell surface expression of ROR1.

Discovery of 2-(Anilino)pyrimidine-4-carboxamides as Highly Potent, Selective, and Orally Active Glycogen Synthase Kinase-3 (GSK-3) Inhibitors.

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that serves as an important regulator of a broad range of cellular functions. It has been linked to Alzheimer's disease as well as various other diseases, including mood disorders, type 2 diabetes, and cancer. There is considerable evidence indicating that GSK-3ß in the central nervous system plays a role in the production of abnormal, hyperphosphorylated, microtubule-associated tau protein found in neurofibrillary tangles associated with Alzheimer's disease. A series of analogues containing a pyrimidine-based hinge-binding heterocycle was synthesized and evaluated, leading to the identification of highly potent GSK-3 inhibitors with excellent kinase selectivity. Further evaluation of 34 and 40 in vivo demonstrated that these compounds are orally bioavailable, brain-penetrant GSK-3 inhibitors that lowered levels of phosphorylated tau in a triple-transgenic mouse Alzheimer's disease model.

Design, Structure-Activity Relationships, and In Vivo Evaluation of Potent and Brain-Penetrant Imidazo[1,2-b]pyridazines as Glycogen Synthase Kinase-3ß (GSK-3ß) Inhibitors.

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that regulates numerous cellular processes, including metabolism, proliferation, and cell survival. Due to its multifaceted role, GSK-3 has been implicated in a variety of diseases, including Alzheimer's disease, type 2 diabetes, cancer, and mood disorders. GSK-3ß has been linked to the formation of the neurofibrillary tangles associated with Alzheimer's disease that arise from the hyperphosphorylation of tau protein. The design and synthesis of a series of imidazo[1,2-b]pyridazine derivatives that were evaluated as GSK-3ß inhibitors are described herein. Structure-activity relationship studies led to the identification of potent GSK-3ß inhibitors. In vivo studies with 47 in a triple-transgenic mouse Alzheimer's disease model showed that this compound is a brain-penetrant, orally bioavailable GSK-3ß inhibitor that significantly lowered levels of phosphorylated tau.

Discovery of Pyridazinone and Pyrazolo[1,5-a]pyridine Inhibitors of C-Terminal Src Kinase.

C-terminal Src kinase (CSK) functions as a negative regulator of T cell activation through inhibitory phosphorylation of LCK, so inhibitors of CSK are of interest as potential immuno-oncology agents. Screening of an internal kinase inhibitor collection identified pyridazinone lead 1, and a series of modifications led to optimized compound 13. Compound 13 showed potent activity in biochemical and cellular assays in vitro and demonstrated the ability to increase T cell proliferation induced by T cell receptor signaling. Compound 13 gave extended exposure in mice upon oral dosing and produced a functional response (decrease in LCK phosphorylation) in mouse spleens at 6 h post dose.

Discovery of new acylaminopyridines as GSK-3 inhibitors by a structure guided in-depth exploration of chemical space around a pyrrolopyridinone core.

Glycogen synthase kinase-3 (GSK-3) has been proposed to play a crucial role in the pathogenesis of many diseases including cancer, stroke, bipolar disorders, diabetes and neurodegenerative diseases. GSK-3 inhibition has been a major area of pharmaceutical interest over the last two decades. A plethora of reports appeared recently on selective inhibitors and their co-crystal structures in GSK-3ß. We identified several series of promising new GSK-3ß inhibitors from a coherent design around a pyrrolopyridinone core structure. A systematic exploration of the chemical space around the central spacer led to potent single digit and sub-nanomolar GSK-3ß inhibitors. When dosed orally in a transgenic mouse model of Alzheimer's disease (AD), an exemplary compound showed significant lowering of Tau phosphorylation at one of the GSK-3 phosphorylating sites, Ser396. X-ray crystallography greatly aided in validating the binding hypotheses.