A collaborative study between OncoPlex Diagnostics, Vall d´Hebron Institute of Oncology (VHIO), and Memorial Sloan Kettering Cancer Center, with support from the BBVA Foundation, defined for the first time a quantitative HER2 protein level measured by mass spectrometry is associated with longer disease free and overall survival in patients receiving anti-HER2 treatment. Results of the study were presented during the ASCO 2014 Annual Meeting by Dr. Paolo Nuciforo, Principal Investigator of VHIO´s Molecular Oncology Group.
While immunohistochemistry (IHC) is the standard technique for detecting HER2 protein expression, it does not provide absolute quantification of this receptor and is prone to false-positives. Many patients who are classified by IHC as HER2-positive actually express low levels of the receptor which dramatically reduces efficacy of anti-HER2 therapy.
OncoPlex Diagnostics uses the patented Liquid Tissue® process to solubilize formalin-fixed, paraffin-embedded (FFPE) tissue for precise protein quantitation by mass spectrometry analysis. The study analyzed tissue from 60 breast cancer patients previously classified as IHC 3+ and treated with anti-HER2 therapy. The research revealed high variability in HER2 expression within the patient population that had been homogenously classified as 3+ by IHC. Patients with HER2 protein levels greater than or equal to 2758.75 amol/ug, as measured by mass spectrometry, correlated with greater clinical benefit including prolonged survival rates. The ASCO poster presentation is available at OncoPlex Dx HER2 ASCO2014 Collaboration.
"This study provides evidence that quantitative measurement by mass spectrometry of a tumor-driving protein such as HER2 correlates with the clinical benefit associated with HER2 targeted therapy," stated Dr. Jedd Levine, Chief Medical Officer for OncoPlex Diagnostics. The primary investigator, Dr. Nucifiro, explains, "If future (ongoing) studies enrolling a greater number of patients confirm these results, this would represent an important game-changer in how we currently determine HER2 expression levels as well as provide oncologists with further insight to better tailor anti-HER2-based therapies according to HER2 protein levels."