RT Journal Article SR Electronic T1 Gamma delta TCR anti-CD3 bispecific molecules (GABs) as novel immunotherapeutic compounds JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP e003850 DO 10.1136/jitc-2021-003850 VO 9 IS 11 A1 Eline van Diest A1 Patricia Hernández López A1 Angelo D Meringa A1 Anna Vyborova A1 Froso Karaiskaki A1 Sabine Heijhuurs A1 Jan Gumathi Bormin A1 Sanne van Dooremalen A1 Mara J T Nicolasen A1 Lucrezia C D E Gatti A1 Inez Johanna A1 Trudy Straetemans A1 Zsolt Sebestyén A1 Dennis X Beringer A1 Jürgen Kuball YR 2021 UL http://jitc.bmj.com/content/9/11/e003850.abstract AB Background γ9δ2 T cells hold great promise as cancer therapeutics because of their unique capability of reacting to metabolic changes with tumor cells. However, it has proven very difficult to translate this promise into clinical success.Methods In order to better utilize the tumor reactivity of γ9δ2T cells and combine this with the great potential of T cell engager molecules, we developed a novel bispecific molecule by linking the extracellular domains of tumor-reactive γ9δ2TCRs to a CD3-binding moiety, creating gamma delta TCR anti-CD3 bispecific molecules (GABs). GABs were tested in vitro and in vivo for ability to redirect T lymphocytes to a variety of tumor cell lines and primary patient material.Results GABs utilizing naturally occurring high affinity γ9δ2TCRs efficiently induced αβT cell mediated phosphoantigen-dependent recognition of tumor cells. Reactivity was substantially modulated by variations in the Vδ2 CDR3-region and the BTN2A1-binding HV4-region between CDR2 and CDR3 of the γ-chain was crucial for functionality. GABs redirected αβT cells against a broad range of hematopoietic and solid tumor cell lines and primary acute myeloid leukemia. Furthermore, they enhanced infiltration of immune cells in a 3D bone marrow niche and left healthy tissues intact, while eradicating primary multiple myeloma cells. Lastly, GABs constructed from natural high affinity γ9δ2TCR sequences significantly reduced tumor growth in vivo in a subcutaneous myeloma xenograft model.Conclusions We conclude that GABs allow for the introduction of metabolic targeting of cancer cells to the field of T cell engagers.Data sharing not applicable as no datasets generated and/or analyzed for this study.