G-protein-coupled receptor 119 (GPR119) is expressed predominantly in pancreatic β-cells and in enteroendocrine cells in the gastrointestinal tract. GPR119 agonists have been shown to stimulate glucose-dependent insulin release by direct action in the pancreas and to promote secretion of the incretin GLP-1 by action in the gastrointestinal tract. This dual mechanism of action has generated significant interest in the discovery of small molecule GPR119 agonists as a potential new treatment for type 2 diabetes. Herein, we describe the discovery and optimization of a new class of pyridone containing GPR119 agonists. The potent and selective BMS-903452 (42) was efficacious in both acute and chronic in vivo rodent models of diabetes. Dosing of 42 in a single ascending dose study in normal healthy humans showed a dose dependent increase in exposure and a trend toward increased total GLP-1 plasma levels.
Rationale
High tumor expression of programmed cell death protein (PD1) and programmed death‐ligand 1 (PD‐L1) is thought to be associated with positive clinical outcomes after treatment with anti‐PD1 or anti‐PD‐L1 agents. Several sensitive methods based on immunohistochemistry, ligand binding assay (LBA), and liquid chromatography/mass spectrometry involving the measurement of PD1 and PD‐L1 expression have been reported. Here, we expand on the characterization of different tumor types using a highly specific, sensitive, and robust immunoaffinity liquid chromatography/tandem mass spectrometry (IA‐LC/MS/MS)‐based method for the simultaneous quantitation of PD1 and PD‐L1 in tumor tissues.
Methods
Human tumor tissue samples were homogenized using a Precellys Evolution homogenizer. The samples were incubated with anti‐PD1 and anti‐PD‐L1 capture polyclonal antibodies, which were bound to magnetic beads. Following enrichment, samples were digested with trypsin. A Waters iKEY HSS T3 1.8 um (150 μm × 100 mm) column with a gradient flow rate of 3 μL/min was used for chromatographic separation, and a Waters TQ‐S triple quadrupole mass spectrometer was used for detection. Selected reaction monitoring (SRM) transitions with unit resolution for precursor/product ion masses were optimized for PD1 and PD‐L1 surrogate peptides.
Results
The surrogate peptides LAAFPEDR for PD1 and FTVTVPK for PD‐L1 yielded the most intense SRM transitions at m/z 459.7 > 516.2 and m/z 396.2 > 543.3, respectively, and thus were selected for the quantitation of PD1 and PD‐L1. The lower limit of quantitation for PD1 and PD‐L1 was 0.062 ng/mL with an assay range up to 10 ng/mL. Using this method, human PD1 and PD‐L1 were detected and quantified from four different types of tumor tissues. The data show that PD1 expression level was highly correlated with that of PD‐L1 in all tumor tissues analyzed here.
Conclusions
A highly specific and sensitive immunoaffinity microflow LC/MS/MS method for the simultaneous quantification of PD1 and PD‐L1 in tumor tissues was developed and implemented. This method combines the advantage of immuno‐capture for analyte enrichment with the high specificity of detection of multiple surrogate peptides by LC/MS/MS. The quantification of PD1 and PD‐L1 co‐expression in tumor could help evaluate their role in assessing tumor type selection and patient stratification.
Background: S1PR1, a G protein-coupled receptor (GPCR) protein, is a therapeutic target for treatment of autoimmune diseases. As a potential biomarker for drug effect and patient stratification, it is of great significance to measure it in biological samples. However, due to the hydrophobic nature of S1PR1 and the difficulties in extraction and solubilization, as well as low expression levels, quantitative determination of S1PR1 remains challenging. Results: In this work, a peptide immunoaffinity LC–MS/MS method was developed to quantify S1PR1 in biopsy-sized colon samples with an LLOQ of 7.81 pM. Conclusion: Peptide immunoaffinity LC–MS/MS based strategy has achieved the desired sensitivity for low abundance S1PR1, and the same strategy could be applied to quantify S1PR1 in multiple species and other GPCR proteins.
Glucokinase (GK) is a key regulator
of glucose homeostasis, and
its small-molecule activators represent a promising opportunity for
the treatment of type 2 diabetes. Several GK activators have been
advanced into clinical trials and have demonstrated promising efficacy;
however, hypoglycemia represents a key risk for this mechanism. In
an effort to mitigate this hypoglycemia risk while maintaining the
efficacy of the GK mechanism, we have investigated a series of amino
heteroaryl phosphonate benzamides as ‘‘partial”
GK activators. The structure–activity relationship studies
starting from a “full GK activator” 11,
which culminated in the discovery of the “partial GK activator” 31 (BMS-820132), are discussed. The synthesis and in vitro and in vivo preclinical pharmacology
profiles of 31 and its pharmacokinetics (PK) are described.
Based on its promising in vivo efficacy and preclinical
ADME and safety profiles, 31 was advanced into human
clinical trials.
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