An antibody composition for use in treating cancer in a subject that has been subjected to a prior treatment regimen involving an anti-human EGFR antibody, said antibody composition comprising a first anti-human EGFR antibody molecule and a second anti-human EGFR antibody molecule distinct from the first molecule, a) wherein the first anti-human EGFR antibody molecule is selected from the group consisting of: i) an antibody whose light chain comprises amino acids 3-216 of SEQ ID NO: 72, and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-109 of SEQ ID NO: 72 and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 72 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 40; and b) wherein the second anti-human EGFR antibody molecule is selected from the group consisting of: i) an antibody whose light chain comprises amino acids 3-221 of SEQ ID NO: 73, and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-114 of SEQ ID NO: 73 and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 73 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 41. a) wherein the first anti-human EGFR antibody molecule is selected from the group consisting of: i) an antibody whose light chain comprises amino acids 3-216 of SEQ ID NO: 72, and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-109 of SEQ ID NO: 72 and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 72 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 40; and i) an antibody whose light chain comprises amino acids 3-216 of SEQ ID NO: 72, and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-109 of SEQ ID NO: 72 and whose heavy chain comprises amino acids 3-124 of SEQ ID NO: 40; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 72 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 40; and b) wherein the second anti-human EGFR antibody molecule is selected from the group consisting of: i) an antibody whose light chain comprises amino acids 3-221 of SEQ ID NO: 73, and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-114 of SEQ ID NO: 73 and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 73 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 41. i) an antibody whose light chain comprises amino acids 3-221 of SEQ ID NO: 73, and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41 and the amino acid sequence of SEQ ID NO: 91; ii) an antibody whose light chain comprises amino acids 3-114 of SEQ ID NO: 73 and whose heavy chain comprises amino acids 3-120 of SEQ ID NO: 41; and iii) an antibody having the light chain CDR1, CDR2, and CDR3 in SEQ ID NO: 73 and the heavy chain CDR1, CDR2, and CDR3 in SEQ ID NO: 41.