Antibodies that bind to cleaved form of mutant calreticulin, and diagnostic, preventive, or therapeutic agent for myeloproliferative neoplasm

An antibody or a functional fragment thereof that binds to a cleaved mutant CALR polypeptide, said antibody or functional fragment thereof selected from the group consisting of (c), (d), and (e):

• (c) an antibody in which CDR1, CDR2, and CDR3 of the immunoglobulin VH chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 17, 18, and 19, respectively, and CDR1, CDR2, and CDR3 of the immunoglobulin VL chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 26, 27, and 28, respectively;
• (d) an antibody in which CDR1, CDR2, and CDR3 of the immunoglobulin VH chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 20, 21, and 22, respectively;
• and CDR1, CDR2, and CDR3 of the immunoglobulin VL chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 29, 30, and 31, respectively;
• and
• (e) an antibody in which CDR1, CDR2, and CDR3 of the immunoglobulin VH chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 23, 24, and 25, respectively;
• and CDR1, CDR2, and CDR3 of the immunoglobulin VL chain are polypeptides consisting of the amino acid sequences set forth in SEQ ID NOs:
• 32, 33, and 34, respectively.