title: Analytical Validation of a Highly Quantitative, Sensitive, Accurate, and Reproducible Assay (HERmark) for the Measurement of HER2 Total Protein and HER2 Homodimers in FFPE Breast Cancer Tumor Specimens.
abstract: We report here the results of the analytical validation of assays that measure HER2 total protein (H2T) and HER2 homodimer (H2D) expression in Formalin Fixed Paraffin Embedded (FFPE) breast cancer tumors as well as cell line controls. The assays are based on the VeraTag technology platform and are commercially available through a central CAP-accredited clinical reference laboratory. The accuracy of H2T measurements spans a broad dynamic range (2-3 logs) as evaluated by comparison with cross-validating technologies. The measurement of H2T expression demonstrates a sensitivity that is approximately 7-10 times greater than conventional immunohistochemistry (IHC) (HercepTest). The HERmark assay is a quantitative assay that sensitively and reproducibly measures continuous H2T and H2D protein expression levels and therefore may have the potential to stratify patients more accurately with respect to response to HER2-targeted therapies than current methods which rely on semiquantitative protein measurements (IHC) or on indirect assessments of gene amplification (FISH).
authors.affiliation: Department of Clinical Laboratory Operations, Monogram Biosciences, Inc., South San Francisco, CA 94080, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Larson
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Goodman
authors.forename: Yuping
authors.initials: Y
authors.lastname: Tan
authors.forename: Lisa
authors.initials: L
authors.lastname: Defazio-Eli
authors.forename: Agnes C
authors.initials: AC
authors.lastname: Paquet
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Cook
authors.forename: Amber
authors.initials: A
authors.lastname: Rivera
authors.forename: Kristi
authors.initials: K
authors.lastname: Frankson
authors.forename: Jolly
authors.initials: J
authors.lastname: Bose
authors.forename: Lili
authors.initials: L
authors.lastname: Chen
authors.forename: Judy
authors.initials: J
authors.lastname: Cheung
authors.forename: Yining
authors.initials: Y
authors.lastname: Shi
authors.forename: Sarah
authors.initials: S
authors.lastname: Irwin
authors.forename: Linda D B
authors.initials: LD
authors.lastname: Kiss
authors.forename: Weidong
authors.initials: W
authors.lastname: Huang
authors.forename: Shannon
authors.initials: S
authors.lastname: Utter
authors.forename: Thomas
authors.initials: T
authors.lastname: Sherwood
authors.forename: Michael
authors.initials: M
authors.lastname: Bates
authors.forename: Jodi
authors.initials: J
authors.lastname: Weidler
authors.forename: Gordon
authors.initials: G
authors.lastname: Parry
authors.forename: John
authors.initials: J
authors.lastname: Winslow
authors.forename: Christos J
authors.initials: CJ
authors.lastname: Petropoulos
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Whitcomb