Anti-CD19 Monoclonal antibody, clone IJC20 [PerCP/Cy5.5®]

Therapies that bind with immune cells and redirect their cytotoxic activity toward diseased cells represent a promising and versatile approach to immunotherapy with applications in cancer, lupus, and other diseases; traditional methods for discovering these therapies, however, are often time-intensive and lack the throughput of related target-based discovery approaches. Inspired by the observation that the cytokine, IL-12, can enhance antileukemic activity of the clinically approved T cell redirecting therapy, blinatumomab, here we describe the structure and assembly of a chimeric immune cell-redirecting agent which redirects the lytic activity of primary human T cells toward leukemic B cells and simultaneously cotargets the delivery of T cell-stimulating IL-12. We further describe a novel method for the parallel assembly of compositionally diverse libraries of these bispecific T cell engaging cytokines (BiTEoldnes) and their high-throughput phenotypic screening, requiring just days for hit identification and the analysis of composition-function relationships. Using this approach, we identified CD19 x CD3 x IL12 compounds that exhibit ex vivo lytic activity comparable to current FDA-approved therapies for leukemia and correlated drug treatment with specific cell-cell contact, cytokine delivery, and leukemia cell lysis. Given the modular nature of these multivalent compounds and their rapid assembly/screening, we anticipate facile extension of this therapeutic approach to a wide range of immune cells, diseased cells, and soluble protein combinations in the future.

Purpose of review Despite considerable therapeutic advances over the last decade, multiple myeloma remains an incurable disease. Novel treatment strategies are urgently needed. T cells can be genetically modified to express chimeric antigen receptors (CARs) targeting defined surface antigens on tumor cells. To date, over 90 clinical trials investigating the use of CAR T cells in multiple myeloma have been registered. Recent findings Although two CD19-directed CAR T-cell products have been approved, CD19 surface expression on plasma cells is limited or absent and CAR T-cell therapy in multiple myeloma is less advanced. B-cell maturation antigen (BCMA)-directed CAR T cells have shown promising efficacy and safety profiles in various phase I/II clinical trials. However, almost all treated patients continue to relapse. The current focus is therefore on strategies to overcome resistance mechanisms. These include the targeting of other surface antigens, refinements in T-cell signaling and dual-targeting approaches. CAR T-cell therapy has finally moved into routine clinical use, the first experiments having taken place over 30 years ago. A BCMA-directed product for the treatment of multiple myeloma is expected to be approved shortly. However, further refinements of both CAR T-cell constructs and treatment protocols will be required to boost persistence, overcome resistance and reduce toxicities.