Monoclonal antibodies against her2 epitope

A nucleic acid encoding a heavy and/or light chain variable region of an antibody which binds to human epidermal growth factor receptor 2 (HER2), wherein the antibody comprises heavy and light chain variable regions selected from the group consisting of:

• a) SEQ ID NOs:
• 1 and 5,
• b) SEQ ID NOs:
• 8 and 12,
• c) SEQ ID NOs:
• 15 and 19,
• d) SEQ ID NOs:
• 22 and 26,
• e) SEQ ID NOs:
• 29 and 33,
• f) SEQ ID NOs:
• 36 and 40,
• g) SEQ ID NOs:
• 43 and 44,
• h) SEQ ID NOs:
• 45 and 46,
• i) SEQ ID NOs:
• 47 and 48,
• j) SEQ ID NOs:
• 49 and 50,
• k) SEQ ID NOs:
• 51 and 52,
• l) SEQ ID NOs:
• 53 and 54, and
• m) SEQ ID NOs:
• 55 and 56.

An expression vector, or set of expression vectors, which encodes an antibody which blocks the binding of a reference antibody to soluble human epidermal growth factor receptor 2 (HER2), wherein the reference antibody comprises heavy chain variable (VH) and light chain variable (VL) regions selected from the group consisting of:

• a) a VH region comprising the sequence of SEQ ID NO:1 and a VL region comprising the sequence of SEQ ID NO:5;
• b) a VH region comprising the sequence of SEQ ID NO:8 and a VL region comprising the sequence of SEQ ID NO:12;
• c) a VH region comprising the sequence of SEQ ID NO:15 and a VL region comprising the sequence of SEQ ID NO:19;
• d) a VH region comprising the sequence of SEQ ID NO:22 and a VL region comprising the sequence of SEQ ID NO:26;
• e) a VH region comprising the sequence of SEQ ID NO:29 and a VL region comprising the sequence of SEQ ID NO:33;
• and
• f) a VH region comprising the sequence of SEQ ID NO:36 and a VL region comprising the sequence of SEQ ID NO:40;
• optionally when determined as described in Example 14.

A recombinant host cell which produces an antibody which blocks the binding of a reference antibody to soluble human epidermal growth factor receptor 2 (HER2), wherein the reference antibody comprises heavy chain variable (VH) and light chain variable (VL) regions selected from the group consisting of:

• a) a VH region comprising the sequence of SEQ ID NO:1 and a VL region comprising the sequence of SEQ ID NO:5;
• b) a VH region comprising the sequence of SEQ ID NO:8 and a VL region comprising the sequence of SEQ ID NO:12;
• c) a VH region comprising the sequence of SEQ ID NO:15 and a VL region comprising the sequence of SEQ ID NO:19;
• d) a VH region comprising the sequence of SEQ ID NO:22 and a VL region comprising the sequence of SEQ ID NO:26;
• e) a VH region comprising the sequence of SEQ ID NO:29 and a VL region comprising the sequence of SEQ ID NO:33;
• and
• f) a VH region comprising the sequence of SEQ ID NO:36 and a VL region comprising the sequence of SEQ ID NO:40;
• optionally when determined as described in Example 14.