C225 antiepidermal growth factor receptor antibody enhances tumor radiocurability

Int J Radiat Oncol Biol Phys. 2001 Oct 1;51(2):474-7. doi: 10.1016/s0360-3016(01)01671-6.


Purpose: Overexpression of epidermal growth factor receptor (EGFR) has been correlated with tumor resistance to radiation. Blockade of EGFR with C225 anti-EGFR antibody was previously shown to synergistically enhance radiation-induced tumor growth delay. The purpose of this study was to assess whether C225 can increase tumor cure by radiation.

Methods and materials: Nude mice bearing 8-mm-diameter A431 tumor xenografts in the hind leg were treated with C225 antibody, graded single doses of local tumor irradiation, or both. C225 was given i.p. at a dose of 1 mg/mouse 6 h before irradiation or 6 h before and 3 plus 6 days after irradiation. Tumor cure was the treatment endpoint assessed by the TCD(50) assay 120 days after treatment. The onset of recurrences of tumors not cured was also determined.

Results: C225 antibody increased the antitumor effects of radiation by reducing TCD(50) values and delaying tumor recurrences. Tumor radiocurability was enhanced by a factor of 1.18 by a single dose and by a factor of 1.92 by three doses of C225. Likewise, the appearance of tumor recurrences was delayed by a factor of 1.37 by a single dose and by a factor of 2.13 by three doses of C225.

Conclusion: The data presented here demonstrate that C225 can increase tumor radiocurability and delay the appearance of recurrences of tumors not cured by radiation treatment.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents / therapeutic use*
  • Cetuximab
  • Dose-Response Relationship, Radiation
  • ErbB Receptors / antagonists & inhibitors*
  • Humans
  • Male
  • Mice
  • Mice, Nude
  • Neoplasm Proteins / antagonists & inhibitors*
  • Neoplasm Recurrence, Local / prevention & control
  • Neoplasms / chemistry
  • Neoplasms / radiotherapy*
  • Radiobiology
  • Radiotherapy Dosage
  • Transplantation, Heterologous


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents
  • Neoplasm Proteins
  • ErbB Receptors
  • Cetuximab