TY  - JOUR
A1  - Rasche, Leo
A1  - Duell, Johannes
A1  - Morgner, Charlotte
A1  - Chatterjee, Manik
A1  - Hensel, Frank
A1  - Rosenwald, Andreas
A1  - Einsele, Hermann
A1  - Topp, Max S.
A1  - Brändlein, Stephanie
T1  - The Natural Human IgM Antibody PAT-SM6 Induces Apoptosis in Primary Human Multiple Myeloma Cells by Targeting Heat Shock Protein GRP78
JF  - PLoS ONE
N2  - In contrast to other haematological malignancies, targeted immunotherapy has not entered standard treatment regimens for de novo or relapsed multiple myeloma (MM) yet. While a number of IgG-formatted monoclonal antibodies are currently being evaluated in clinical trials in MM, our study aimed to investigate whether the fully human IgM monoclonal antibody PAT-SM6 that targets a tumour-specific variant of the heat shock protein GRP78 might be an attractive candidate for future immunotherapeutic approaches. We here show that GRP78 is stably and consistently expressed on the surface on tumour cells from patients with de novo, but also relapsed MM and that binding of PAT-SM6 to MM cells can specifically exert cytotoxic effects on malignant plasma cells, whereas non-malignant cells are not targeted. We demonstrate that the induction of apoptosis and, to a lesser extent, complement dependent cytotoxicity is the main mode of action of PAT-SM6, whereas antibody dependent cellular cytotoxicity does not appear to contribute to the cytotoxic properties of this antibody. Given the favourable safety profile of PAT-SM6 in monkeys, but also in a recent phase I trial in patients with malignant melanoma, our results form the basis for a planned phase I study in patients with relapsed MM.
KW  - cytotoxicity
KW  - apoptosis
KW  - immunohistochemistry techniques
KW  - enzyme-linked immunoassays
KW  - multiple myeloma
KW  - cell staining
KW  - cell binding
KW  - complement system
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130125
VL  - 8
IS  - 5
ER  -