An Automated Multicycle Immunoaffinity Enrichment Approach Developed for Sensitive Mouse IgG1 Antibody Drug Analysis in Mouse Plasma Using LC/MS/MS.

In the immuno-oncology field, surrogate mouse monoclonal antibodies are often preferred in establishing proper PK/PD/efficacy correlations as well as supporting anticipated mouse to human translation. Thus, a highly sensitive and specific bioanalytical method is needed in quantifying those surrogate mouse antibodies after dosing in mice. Unfortunately, when specific reagents, such as recombinant target antigen and anti-idiotypic antibody, are not available, measuring mouse surrogate antibody drugs in mice is very challenging for ligand binding assay (LBA) due to the severe cross reactivity potential.

A Citrulline-Based Translational Population System Toxicology Model for Gastrointestinal-Related Adverse Events Associated With Anticancer Treatments.

Gastrointestinal (GI)-related adverse events (AEs) are commonly observed in the clinic during cancer treatments. Citrulline is a potentially translatable biomarker of GI AEs. In this study, irinotecan-induced citrulline changes were studied for a range of doses and schedules in rats.

An LC/MS based method to quantify DNA adduct in tumor and organ tissues.

Highly potent DNA damaging agents have become a key class of toxins for antibody-drug conjugate (ADC) based targeted therapy. However, until recently, no quantitative bioanalytical method was available to measure the toxin in the form of DNA adducts. In this work, a novel microwave assisted organic solvent extraction and LC-MS/MS based bioanalytical method was developed to extract and quantify DNA-bound toxin IGN-P1 in tissue samples.

A generic approach for simultaneous measurements of total antibody and cleavable antibody-conjugated drug by LC/MS/MS.

The current industry practice for antibody-drug conjugate (ADC) bioanalysis includes quantification of total antibody and antibody-conjugated drug. Here, we report a novel 2-in-1 approach for measuring total antibody and protease-cleavable conjugated drug Monomethyl Auristatin E (MMAE) concurrently. This allows for the determination of the DAR (Drug Antibody Ratio) for in vivo samples, with a 3-orders linear range based on total antibody concentration from 0.

Mechanistic evaluation of substrate inhibition kinetics observed from aldehyde oxidase-catalyzed reactions.

While most enzyme-catalyzed reactions are adequately described by Michaelis-Menten kinetics, Aldehyde Oxidase (AOX) metabolism might exhibit atypical kinetics due to possible substrate inhibition. Ignoring this phenomenon may lead to erroneous estimates of kinetic parameters and over simplification of the enzyme mechanism. In this study, in vitro metabolism data for 3 AOX substrates exhibiting varying degrees of substrate inhibition were analyzed with the following kinetic models: A) Michaelis-Menten (naïve) model; B) Substrate inhibition (empirical) model; and C) Twobinding site (mechanistic) model.