A novel proximity assay for the detection of proteins and protein complexes: quantitation of HER1
and HER2 total protein expression and homodimerization in formalin-fixed, paraffin-embedded cell lines and breast cancer tissue.
blockers, such as Genentech's erlotinib, AstraZeneca's gefitinib, ImClone's cetuximab and Amgen's panitumumab arrest and aggregate HER1
overexpressing cancer cells in the G1-Phase.
Conduct additional studies in both metastatic and adjuvant breast cancer using an expanded menu of VeraTag assays (which may include: HER2 total protein and homodimer, HER1
total protein and homodimer, HER3 total protein, HER1
:2 and HER2:3 heterodimers, HER3-PI3K, and p95) to investigate why patients fail targeted therapies, and thus to understand how targeted inhibitors of the EGFR-family of receptors might be combined for better patient outcomes.
Erlotinib has also been used in combination with trastuzumab  or with bevacizumab , and an anti-cancer effect was observed in some patients although it remains unclear whether HER1
is a target.
Additionally, the study aims to describe the expression/co-expression profiles identified by Monogram's HER1
and HER3 Total Protein Assays along with HER2 total protein and homodimer levels identified by HERmark to facilitate analyses of how such measurements may correlate with certain laboratory and clinical parameters, including disease progression.
In addition, however, HER2 is also a favoured heterodimer partner for HER1
, HER3 or HER4.
EZN-3920 may provide a novel strategy to overcome resistance to HER1
and HER2 targeted therapies.
Neratinib is a potent irreversible tyrosine kinase inhibitor that blocks signal transduction through the epidermal growth factor receptors, HER1
, HER2 and HER4.
Lapatinib is an orally active competitive inhibitor of both HER1
and HER2 tyrosine kinases.
Data from the BR9601 trial  suggest that HER1
and HER3 provide additional information when analysed with HER2, building on the hypothesis that these type I receptor tyrosine kinases are associated with pathway activation and a common resistance phenotype [26-28].
HER2 is part of a super-family of tyrosine kinase receptors which includes HER1
, HER3 and HER4.
ERBITUX (cetuximab) is a monoclonal antibody (IgG1 Mab) designed to inhibit the function of a molecular structure expressed on the surface of normal and tumor cells called the epidermal growth factor receptor (EGFR, HER1