Pharmacokinetic analysis of a novel human EGFRvIII:CD3 bispecific antibody in plasma and whole blood using a high-resolution targeted mass spectroscopy approach

ABSTRACT: Bi-specific single change antibody fragments (bi-scFv) represent an emerging class of biotherapeutics. We recently developed a fully human bi-scFv (EGFRvIII:CD3 bi-scFv) with the goal of redirecting CD3-expressiong T cells to recognize and destroy malignant, EGFR-expressing glioma. In mice, we showed that EGFRvIII:CD3 bi-scFv effectively treats orthotopic patient-derived malignant glioma and syngeneic glioblastoma. Here, we sought to develop a targeted assay for pharmacokinetic (PK) analysis of EGFRvIII:CD3 bi-scFv, a necessary step in the drug development process. Using microflow liquid chromatography coupled to high resolution parallel reaction monitoring mass spectrometry, and data analysis in Skyline, we developed a bottom-up proteomic assay for quantification of EGFRvIII:CD3 bi-scFv in both plasma and whole blood. Importantly, a protein calibrator, along with stable isotope-labeled EGFRvIII:CD3 bi-scFv protein, were used for absolute quantification. A PK analysis in a CD3 humanized mouse revealed that EGFRvIII:CD3 bi-scFv in plasma and whole blood has an initial half-life of ~8 minutes and a terminal half-life of ~2.5 hours. Our results establish a sensitive, high-throughput assay for direct quantification of EGFRvIII:CD3 bi-scFv without the need for immunoaffinity enrichment. Moreover, these half-life measurements will guide drug optimization and dosing regimens in future pre-clinical and Phase 0/I studies of EGFRvIII:CD3 bi-scFv

ORGANISM(S): Homo Sapiens Mus Musculus

SUBMITTER: Matt Foster  

PROVIDER: PXD012472 | panorama | Tue Jul 09 00:00:00 BST 2019

REPOSITORIES: PanoramaPublic