12th GCC Closed Forum: critical reagents; oligonucleotides; CoA; method transfer; HRMS; flow cytometry; regulatory findings; stability and immunogenicity.

The 12th GCC Closed Forum was held in Philadelphia, PA, USA, on 9 April 2018. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: critical reagents; oligonucleotides; certificates of analysis; method transfer; high resolution mass spectrometry; flow cytometry; recent regulatory findings and case studies involving stability and nonclinical immunogenicity. Conclusions and consensus from discussions of these topics are included in this article.

Recommendations for classification of commercial LBA kits for biomarkers in drug development from the GCC for bioanalysis.

Over the last decade, the use of biomarker data has become integral to drug development. Biomarkers are not only utilized for internal decision-making by sponsors; they are increasingly utilized to make critical decisions for drug safety and efficacy. As the regulatory agencies are routinely making decisions based on biomarker data, there has been significant scrutiny on the validation of biomarker methods. Contract research organizations regularly use commercially available immunoassay kits to validate biomarker methods. However, adaptation of such kits in a regulated environment presents significant challenges and was one of the key topics discussed during the 12th Global Contract Research Organization Council for Bioanalysis (GCC) meeting. This White Paper reports the GCC members' opinion on the challenges facing the industry and the GCC recommendations on the classification of commercial kits that can be a win-win for commercial kit vendors and end users.

Real-time quantitation of viral replication and inhibitor potency using a label-free optical biosensor.

Real-time detection of viral replication inside cells remains a challenge to researchers. The Epic System is a high-throughput, label-free optical detection platform capable of measuring molecular interaction in a biochemical assay, as well as integrated cellular response from measurement of cellular dynamic mass redistribution (DMR) in a cell-based assay. DMR has previously been used to measure cell signaling upon receptor stimulation. In this report, we present the first example of Epic measurement of viral replication-induced cellular response and demonstrate that this system is extremely powerful not only for the sensitive and quantitative detection of viral replication inside cells but also for screening of viral inhibitors. By comparing with conventional assays used for the measurement of viral replication, we show that the Epic response has many advantages including sensitivity, high throughput, real-time quantification and label-free detection. We propose that the Epic system for measurement of integrated cellular response will be an excellent method for elucidating steps in viral replication as well as for the high-throughput screening of inhibitors of rhinovirus and other viruses.

Evaluation of dynamic mass redistribution technology for pharmacological studies of recombinant and endogenously expressed g protein-coupled receptors.

The Epic cell assay technology (Corning Inc., Corning, NY) uses a resonant waveguide grating optical biosensor to measure cellular response to ligands manifested through dynamic mass redistribution (DMR) of cellular contents. The DMR measurement is a noninvasive, label-free assay that can be used to assess the pharmacological properties of compounds. In this study, a panel of 12 compounds was evaluated against two G protein-coupled receptor (GPCR) targets in recombinant expressed cell lines using the Corning Epic system in 384-well microplates. The evaluation was performed in a double-blinded fashion such that the identity and properties of both the GPCR targets and compounds were unknown to the researchers at the time of the study. Analysis of the DMR response from cell stimulation was used to identify compounds that functioned as agonists or antagonists and to evaluate the associated efficacy and potency. DMR results were shown to have good agreement with data obtained from cyclic AMP and calcium flux assays for compounds evaluated. A further analysis was performed and successfully identified the signaling pathways that the two GPCRs activated. In addition, the DMR measurement was able to detect responses from an endogenous receptor in these cells. The Epic DMR technology provides a generic platform amenable to pharmacological evaluation of cellular responses to GPCR activation in a label-free live cell assay format.

Apo-AII is an elevated biomarker of chronic non-human primate ethanol self-administration.

AIMS: Serum protein profiles were examined in naïve, ethanol self-administering and ethanol abstinent cynomolgus monkeys (Macaca fasicularis) to search for differences in protein expression which could possibly serve as biomarkers of heavy ethanol consumption. METHODS: Surface-enhanced laser desorption ionization time-of-flight (SELDI-ToF) mass spectrometry was used for proteomic profiling of serum. RESULTS: Two proteins were identified by SELDI-ToF to be increased in ethanol self-administering compared with abstinent animals. These proteins were identified to be apolipoprotein AI (Apo-AI) and apolipoprotein AII (Apo-AII) by peptide mass fingerprinting and comparison with spectra of purified human Apo-AI and AII proteins. Immunoblot analysis of Apo-AI and Apo-AII was performed on a separate group of animals (within-animal ethanol-naïve and self-administering) and confirmed a statistically significant increase in Apo-AII, while Apo-AI was unchanged. CONCLUSIONS: An open proteomic screen of serum and confirmation in a separate set of animals found Apo-AII to be increased in the serum of ethanol self-administering monkeys. These results are consistent with previous clinical studies of human ethanol consumption and serum apolipoprotein expression. Moreover, these results validate the use of non-human primates as a model organism for proteomic analysis of ethanol self-administration biomarkers.