@article{BraigKriegsVoigtlaenderetal.2017,
  author    = {Braig, Friederike and Kriegs, Malte and Voigtlaender, Minna and Habel, Beate and Grob, Tobias and Biskup, Karina and Blanchard, Veronique and Sack, Markus and Thalhammer, Anja and Ben Batalla, Isabel and Braren, Ingke and Laban, Simon and Danielczyk, Antje and Goletz, Steffen and Jakubowicz, Elzbieta and Maerkl, Bruno and Trepel, Martin and Knecht, Rainald and Riecken, Kristoffer and Fehse, Boris and Loges, Sonja and Bokemeyer, Carsten and Binder, Mascha},
  title     = {Cetuximab Resistance in Head and Neck Cancer Is Mediated by EGFR-K-521 Polymorphism},
  series = {Cancer research},
  volume    = {77},
  journal   = {Cancer research},
  number    = {5},
  publisher = {American Association for Cancer Research},
  address   = {Philadelphia},
  issn      = {0008-5472},
  doi       = {10.1158/0008-5472.CAN-16-0754},
  pages     = {1188 -- 1199},
  year      = {2017},
  abstract  = {Head and neck squamous cell carcinomas (HNSCC) exhibiting resistance to the EGFR-targeting drug cetuximab poses a challenge to their effective clinical management. Here, we report a specific mechanism of resistance in this setting based upon the presence of a single nucleotide polymorphism encoding EGFR-K-521 (K-allele), which is expressed in > 40\% of HNSCC cases. Patients expressing the K-allele showed significantly shorter progressionfree survival upon palliative treatment with cetuximab plus chemotherapy or radiation. In several EGFR-mediated cancer models, cetuximab failed to inhibit downstream signaling or to kill cells harboring a high K-allele frequency. Cetuximab affinity for EGFR-K-521 was reduced slightly, but ligand-mediated EGFR acti-vation was intact. We found a lack of glycan sialyation on EGFR-K-521 that associated with reduced protein stability, suggesting a structural basis for reduced cetuximab efficacy. CetuGEX, an antibody with optimized Fc glycosylation targeting the same epitope as cetuximab, restored HNSCC sensitivity in a manner associated with antibody-dependent cellular cytotoxicity rather than EGFR pathway inhibition. Overall, our results highlight EGFR-K-521 expression as a key mechanism of cetuximab resistance to evaluate prospectively as a predictive biomarker in HNSCC patients. Further, they offer a preclinical rationale for the use of ADCC-optimized antibodies to treat tumors harboring this EGFR isoform.},
  language  = {en}
}