CS-1 Is Expressed in Nasal Type NK/T Cell Lymphomas and Angioimmunoblastic T-Cell Lymphomas: Implications for Targeted Therapy with Elotuzumab (HuLuc63).

Background:CS-1 (CRACC, SLAMF7, CD319) is a member of the signaling lymphocyte activating molecule-related receptor family. It is highly and uniformly expressed on the cell surface of benign and malignant plasma cells. We have recently reported the generation of elotuzumab (formerly known as HuLuc63), a humanized antibody targeting CS-1, which is currently in phase 1 trials in relapsed multiple myeloma. Lower levels of CS-1 have also been reported on NK cells and NK-like T-cells (NK/T). CS-1 expression in NK and T-cell lymphomas - aggressive lymphomas for which no effective therapy exists - is unknown. Here, we examined the expression of CS-1 in normal NK/T cells and in a series of NK and peripheral T-cell lymphomas (PTCL).