A sensitive method for the quantitation of the peptide-based glucagon-like peptide-1 receptor agonist liraglutide in plasma using microfluidics chromatography tandem MS

GIPR antagonist antibodies conjugated to GLP-1 peptide are bispecific molecules that decrease weight in obese mice and monkeys

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) regulate glucose and energy homeostasis. Targeting both pathways with GIP receptor (GIPR) antagonist antibody (GIPR-Ab) and GLP-1 receptor (GLP-1R) agonist, by generating GIPR-Ab/GLP-1 bispecific molecules, is an approach for treating obesity and its comorbidities. In mice and monkeys, these molecules reduce body weight (BW) and improve many metabolic parameters. BW loss is greater with GIPR-Ab/GLP-1 than with GIPR-Ab or a control antibody conjugate, suggesting synergistic effects. GIPR-Ab/GLP-1 also reduces the respiratory exchange ratio in DIO mice. Simultaneous receptor binding and rapid receptor internalization by GIPR-Ab/GLP-1 amplify endosomal cAMP production in recombinant cells expressing both receptors. This may explain the efficacy of the bispecific molecules. Overall, our GIPR-Ab/GLP-1 molecules promote BW loss, and they may be used for treating obesity.

An ultrasensitive UPLC–MS/MS assay for the quantification of the therapeutic peptide liraglutide in plasma to assess the oral and nasal bioavailability in beagle dogs

Aim: An ultrasensitive UPLC–MS/MS assay for liraglutide was developed and validated according to US FDA and EMA guidelines and applied to the quantification of plasma concentrations after intravenous, nasal and oral administration of liraglutide to beagle dogs. Results: Liraglutide isolation was performed with a combined protein precipitation and solid-phase extraction protocol. The calibrated concentration range of 0.1–200 ng/ml was linear with correlation coefficients >0.998. Precise analysis was achieved through the utilization of an isotopically labeled internal standard. Absolute bioavailability of liraglutide after nasal and oral administration of liraglutide to beagle dogs was 0.03 and 0.006%, respectively. Conclusion: The assay matches the performance in sensitivity of the previously applied immunoassay and optimally covers the therapeutic range of liraglutide.