We have evaluated the carbohydrate antigen Lewis Y (Le Y) as a potential target for T-cell immunotherapy of hematological neoplasias. Analysis of 81 primary bone marrow samples revealed moderate Le Y expression on plasma cells of myeloma patients and myeloblasts of patients with acute myeloid leukemia (AML)(52 and 46% of cases, respectively). We developed a retroviral vector construct encoding a chimeric T-cell receptor that recognizes the Le Y antigen in a major histocompatibility complex-independent manner and delivers co-stimulatory signals to achieve T-cell activation. We have shown efficient transduction of peripheral blood-derived T cells with this construct, resulting in antigen-restricted interferon-γ secretion and cell lysis of Le Y-expressing tumor cells. In vivo activity of gene-modified T cells was demonstrated in the delayed growth of myeloma xenografts in NOD/SCID mice, which prolonged survival. Therefore, targeting Le Y-positive malignant cells with T cells expressing a chimeric receptor recognizing Le Y was effective both in vitro and in a myeloma mouse model. Consequently, we plan to use T cells manufactured under Good Manufacturing Practice conditions in a phase I immunotherapy study for patients with Le Y-positive myeloma or AML.