ANTI-BCMA ANTIBODIES

1 . An isolated polypeptide comprising an antigen binding fragment of an antibody that binds to the polypeptide of SEQ ID NO:9, wherein antigen binding fragment of the antibody comprises:

a) a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 1 and a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 2;

b) a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO:3 and a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NOs: 4, 11, or12;

c) a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 5 and a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 6; or

d) a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 7 and a variable domain comprising CDR1, CDR2, and CDR3 of the amino acid sequence of SEQ ID NO: 8.

2 . The isolated polypeptide of claim 1 , wherein the heavy chain variable domain comprises SEQ ID NO: 1 and the light chain variable domain comprises SEQ ID NO: 2.

3 . The isolated polypeptide of claim 1 , wherein the heavy chain variable domain comprises SEQ ID NO: 3 and the light chain variable domain comprises SEQ ID NOs: 4, 11, or 12.

4 . The isolated polypeptide of claim 1 , wherein the heavy chain variable domain comprises SEQ ID NO: 5 and the light chain variable domain comprises SEQ ID NO: 6.

5 . The isolated polypeptide of claim 1 , wherein the heavy chain variable domain comprises SEQ ID NO: 7 and the light chain variable domain comprises SEQ ID NO: 8.

6 . The isolated polypeptide of claim 1 , wherein antigen binding fragment of the antibody is chimeric, humanized, or a single chain antigen binding fragment.

7 . The isolated polypeptide of claim 1 , wherein antigen binding fragment of the antibody is a Fab fragment, or a F(ab′) 2 fragment.

8 . An isolated polypnucleotide encoding the isolated polypeptide of any one of claims 1 - 7 .

9 . A vector comprising the isolated polynucleotide of claim 8 .

10 . A cell comprising the vector of claim 9 .

11 . A method of treating a B cell-related disorder associated with BCMA expression, comprising administering the isolated polypeptide of claim 1 .

12 . The method of claim 11 , wherein the B-cell related disorder is plasmacytoma, Hodgkins' lymphoma, follicular lymphomas, small non-cleaved cell lymphomas, endemic Burkitt's lymphoma, sporadic Burkitt's lymphoma, marginal zone lymphoma, extranodal mucosa-associated lymphoid tissue lymphoma, nodal monocytoid B cell lymphoma, splenic lymphoma, mantle cell lymphoma, large cell lymphoma, diffuse mixed cell lymphoma, immunoblastic lymphoma, primary mediastinal B cell lymphoma, pulmonary B cell angiocentric lymphoma, small lymphocytic lymphoma, B cell proliferations of uncertain malignant potential, lymphomatoid granulomatosis, post-transplant lymphoproliferative disorder, an immunoregulatory disorder, rheumatoid arthritis, myasthenia gravis, idiopathic thrombocytopenia purpura, anti-phospholipid syndrome, Chagas' disease, Grave's disease, Wegener's granulomatosis, poly-arteritis nodosa, Sjogren's syndrome, pemphigus vulgaris, scleroderma , multiple sclerosis, anti-phospholipid syndrome, ANCA associated vasculitis, Goodpasture's disease, Kawasaki disease, autoimmune hemolytic anemia, and rapidly progressive glomerulonephritis, heavy-chain disease, primary or immunocyte-associated amyloidosis, or monoclonal gammopathy of undetermined significance.

13 . The method of claim 11 , wherein the B cell-related disorder is a B cell malignancy.

14 . The method of claim 11 , wherein the B cell-related disorder is a plasma cell malignancy.

15 . The method of claim 14 , wherein the plasma cell malignancy is multiple myeloma.