We and others have demonstrated that cetuximab resistance in HNSCC is driven by alternative receptor tyrosine kinases (RTK), including HER3, MET, and AXL.
Aberrant HER3 ligand heregulin-expressing head and neck squamous cell carcinoma is resistant to anti-EGFR antibody cetuximab, but not second-generation EGFR-TKI.
The expression of the c-erbB-2, c-erbB-3 and c-erbB-4 members of the epidermal growth factor receptor family was examined in 16 fresh frozen tissue specimens of SCCHN using avidin-biotin complex immunohistochemistry, with monoclonal and/or polyclonal antibodies directed against each.
Dual Targeting of Epidermal Growth Factor Receptor and HER3 by MEHD7945A as Monotherapy or in Combination with Cisplatin Partially Overcomes Cetuximab Resistance in Head and Neck Squamous Cell Carcinoma Cell Lines.
In an effort to elucidate the role of ErbB receptors in human head and neck squamous cell carcinoma (HNSCC), expression abnormalities and subcellular localization of epidermal growth factor receptor (EGFR), ErbB2, ErbB3, and ErbB4 were investigated along with EGF and tenascin by immunohistochemistry in 38 carcinomas as compared to adjacent normal mucosa of 24 cases.
Combined treatment with cetuximab and MM-121 blocked EGFR and HER3 activities and inhibited the PI3K/AKT and ERK signaling pathways and HNSCC cell growth more effectively than each antibody alone.
Thirteen different histological subtypes were affected by ERBB3 mutations; top ones were colorectal carcinomas (6 patients), non-small cell lung cancers (4 patients, including a squamous cell carcinoma), head and neck squamous cell carcinomas (3 patients) and breast carcinomas (3 patients).
Collectively, our findings indicate that evaluation of MET and HER2/HER3 in response to cetuximab in HNSCC patients can provide the rationale of successive line of treatment.
We propose that NRG1 expression and EGFR activation signatures may enrich for improved efficacy of anti-ErbB3 therapeutic mAb approaches when combined with EGFR-targeting therapies in HNSCC.