A high-throughput screening assay for mutant isocitrate dehydrogenase 1 using acoustic droplet ejection mass spectrometry.

Acoustic droplet ejection mass spectrometry (ADE-MS) has recently emerged as a promising label-free, MS-based readout method for high throughput screening (HTS) campaigns in early pharmaceutical drug discovery, since it enables high-speed analysis directly from 384- or 1536-well plates. In this manuscript we describe our characterization of an ADE-MS based high sample content enzymatic assay for mutant isocitrate dehydrogenase 1 (IDH1) R132H with a strong focus on assay development. IDH1 R132H has become a very attractive therapeutic target in the field of antitumor drug discovery, and several pharmaceutical companies have attempted to develop novel small molecule inhibitors against mutant IDH1. With the development of an mIDH1 ADE-MS based HTS assay and a detailed comparison of this new readout technique to the commonly used fluorescence intensity mIDH1 assay, we demonstrated good correlation of both methods and were able to identify new potent inhibitors of mIDH1.

Design, Synthesis, and Pharmacological Evaluation of Potent Positive Allosteric Modulators of the Glucagon-like Peptide-1 Receptor (GLP-1R).

The therapeutic success of peptidic GLP-1 receptor agonists for treatment of type 2 diabetes mellitus (T2DM) motivated our search for orally bioavailable small molecules that can activate the GLP-1 receptor (GLP-1R) as a well-validated target for T2DM. Here, the discovery and characterization of a potent and selective positive allosteric modulator (PAM) for GLP-1R based on a 3,4,5,6-tetrahydro-1H-1,5-epiminoazocino[4,5-b]indole scaffold is reported. Optimization of this series from HTS was supported by a GLP-1R ligand binding model. Biological in vitro testing revealed favorable ADME and pharmacological profiles for the best compound 19. Characterization by in vivo pharmacokinetic and pharmacological studies demonstrated that 19 activates GLP-1R as positive allosteric modulator (PAM) in the presence of the much less active endogenous degradation product GLP1(9-36)NH2 of the potent endogenous ligand GLP-1(7-36)NH2. While these data suggest the potential of small molecule GLP-1R PAMs for T2DM treatment, further optimization is still required towards a clinical candidate.