The Gyrolab™ immunoassay system: a platform for automated bioanalysis and rapid sample turnaround.

BACKGROUND: The Gyrolab™ workstation benefits from fully automated transfer of reagents and samples originating from a storage microplate onto a compact disc containing solid-phase microstructures composed of a 15 nl streptavidin-derivitized bead bed. RESULTS: This paper describes the development, full validation and use of the method in a regulated environment to measure a humanized bispecific monoclonal antibody-domain antibody (GSK-A) molecule using the Gyrolab immunoassay system in cynomolgus nonhuman primate plasma ranging from 5 to 250 µg/ml. The method was subsequently used in support of the TK portion of a regulated preclinical study in monkeys. CONCLUSION: The Gyrolab immunoassay system proved to be a viable alternative to traditional immunoassays and was used to support a regulated preclinical TK study. The speed of analysis that the Gyrolab provides was beneficial in meeting timelines to complete this project as multiple assays and repeat sample analysis could be completed in the same day.

Application of DBS for the quantitative assessment of a protein biologic using on-card digestion LC-MS/MS or immunoassay.

BACKGROUND: Dried blood spot (DBS) sampling has recently gained popularity in the bioanalysis community for quantitation of small molecules. Since the pharmaceutical industry continues to increase investment in biopharmaceuticals, DBS technologies were investigated to determine if immunoassay and/or LC-MS/MS techniques would be amenable for quantitation of a large protein therapeutic (>70 kDa). RESULTS: Methods were successfully qualified for the protein therapeutic utilizing DBS technology. DBS methods in rat blood were qualified for this therapeutic protein using either immunoassay or enzymatic digestion directly off the DBS card followed by UHPLC-MS/MS separation and detection. Both qualifications were carried out in accordance with current acceptable practices defined by international acceptance criteria. Card selection was critical to both DBS methods. CONCLUSION: The advantages gained by DBS technology can successfully be applied to the quantitative assessment of biologics. This UHPLC-MS/MS method illustrates that digestion of large molecules directly off blood spot cards allows quantitation of these molecules. In addition, DBS technologies are amenable to immunoassay analysis. The immunoassay was 20-fold more sensitive than the UHPLC-MS/MS method, however the UHPLC-MS/MS assay had a much broader dynamic range.

Albiglutide, a long lasting glucagon-like peptide-1 analog, protects the rat heart against ischemia/reperfusion injury: evidence for improving cardiac metabolic efficiency.

BACKGROUND: The cardioprotective effects of glucagon-like peptide-1 (GLP-1) and analogs have been previously reported. We tested the hypothesis that albiglutide, a novel long half-life analog of GLP-1, may protect the heart against I/R injury by increasing carbohydrate utilization and improving cardiac energetic efficiency. METHODS/PRINCIPAL FINDINGS: Sprague-Dawley rats were treated with albiglutide and subjected to 30 min myocardial ischemia followed by 24 h reperfusion. Left ventricle infarct size, hemodynamics, function and energetics were determined. In addition, cardiac glucose disposal, carbohydrate metabolism and metabolic gene expression were assessed. Albiglutide significantly reduced infarct size and concomitantly improved post-ischemic hemodynamics, cardiac function and energetic parameters. Albiglutide markedly increased both in vivo and ex vivo cardiac glucose uptake while reducing lactate efflux. Analysis of metabolic substrate utilization directly in the heart showed that albiglutide increased the relative carbohydrate versus fat oxidation which in part was due to an increase in both glucose and lactate oxidation. Metabolic gene expression analysis indicated upregulation of key glucose metabolism genes in the non-ischemic myocardium by albiglutide. CONCLUSION/SIGNIFICANCE: Albiglutide reduced myocardial infarct size and improved cardiac function and energetics following myocardial I/R injury. The observed benefits were associated with enhanced myocardial glucose uptake and a shift toward a more energetically favorable substrate metabolism by increasing both glucose and lactate oxidation. These findings suggest that albiglutide may have direct therapeutic potential for improving cardiac energetics and function.

Absolute quantification of a therapeutic domain antibody using ultra-performance liquid chromatography-mass spectrometry and immunoassay.

BACKGROUND: Domain antibodies (dAbs; ∼10-15 kDa) are made up of the variable heavy chain or the variable light chain of the antibody structure, and retain binding capability. dAbs have proved difficult to detect in plasma using immunoassay without specific antibodies raised against the dAb. RESULTS: A sensitive and selective UPLC-MS/MS method for the absolute quantification of a dAb in monkey plasma was developed (range: 1 to 500 ng/ml) without the need for a specific capture antibody. This method was used to analyze pharmacokinetic studies early on in drug development. Furthermore, an immunoassay was developed and the pharmacokinetic samples were reanalyzed. CONCLUSION: The two assays show good correlation (r(2) = 0.92), giving confidence in using either method for quantification of the dAb.