1. Academic Validation
  2. Membrane-Proximal Epitope Facilitates Efficient T Cell Synapse Formation by Anti-FcRH5/CD3 and Is a Requirement for Myeloma Cell Killing

Membrane-Proximal Epitope Facilitates Efficient T Cell Synapse Formation by Anti-FcRH5/CD3 and Is a Requirement for Myeloma Cell Killing

  • Cancer Cell. 2017 Mar 13;31(3):383-395. doi: 10.1016/j.ccell.2017.02.001.
Ji Li 1 Nicola J Stagg 1 Jennifer Johnston 1 Michael J Harris 2 Sam A Menzies 2 Danielle DiCara 1 Vanessa Clark 1 Maria Hristopoulos 1 Ryan Cook 1 Dionysos Slaga 1 Rin Nakamura 1 Luke McCarty 1 Siddharth Sukumaran 1 Elizabeth Luis 1 Zhengmao Ye 1 Thomas D Wu 1 Teiko Sumiyoshi 1 Dimitry Danilenko 1 Genee Y Lee 1 Klara Totpal 1 Diego Ellerman 1 Isidro Hötzel 1 John R James 2 Teemu T Junttila 3
Affiliations

Affiliations

  • 1 Genentech, Inc., 1 DNA Way, South San Francisco, San Francisco, CA 94080, USA.
  • 2 Molecular Immunity Unit, Department of Medicine, University of Cambridge, MRC-LMB, Cambridge, CB2 0QH, UK.
  • 3 Genentech, Inc., 1 DNA Way, South San Francisco, San Francisco, CA 94080, USA. Electronic address: [email protected].
Abstract

The anti-FcRH5/CD3 T cell-dependent bispecific antibody (TDB) targets the B cell lineage marker FcRH5 expressed in multiple myeloma (MM) tumor cells. We demonstrate that TDBs trigger T cell receptor activation by inducing target clustering and exclusion of CD45 Phosphatase from the synapse. The dimensions of the target molecule play a key role in the efficiency of the synapse formation. The anti-FcRH5/CD3 TDB kills human plasma cells and patient-derived myeloma cells at picomolar concentrations and results in complete depletion of B cells and bone marrow plasma cells in cynomolgus monkeys. These data demonstrate the potential for the anti-FcRH5/CD3 TDB, alone or in combination with inhibition of PD-1/PD-L1 signaling, in the treatment of MM and other B cell malignancies.

Keywords

CD3; FCRL5; FcRH5; T cell; bispecific antibody; multiple myeloma.

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