Monoclonal antibodies directed to a peptide consisting of at least 14 amino acids and a maximum of 50 amino acids selected in sequence from residues 252-322 of the tropomyosin-related kinase B receptor (TrkB) of SEQ ID NO:1 and comprising Asp-298 and Cys-302. Exemplified peptide is from residues 288 to 307 and comprises the sequence: TITFLESPTSDHHWCIPFTV. Fragments of these antibodies, in particular fragments representing complementarity determining regions (CDRs), and proteins comprising these, are useful in a method of treating cancer, pain, anorexia, anorexia nervosa and/or cachexia.
