Vy9V82 T cells are effector cells with proven antitumor efficacy against a broad range of cancers. This study aimed to assess the antitumor activity and safety of a bispecific antibody directing... Show moreVy9V82 T cells are effector cells with proven antitumor efficacy against a broad range of cancers. This study aimed to assess the antitumor activity and safety of a bispecific antibody directing Vy9V82 T cells to EGFR-expressing tumors. An EGFR-V82 bispecific T-cell engager (bsTCE) was generated, and its capacity to activate Vy9V82 T cells and trigger antitumor activity was tested in multiple in vitro, in vivo, and ex vivo models. Studies to explore safety were conducted using cross-reactive surrogate engagers in nonhuman primates (NHP). We found that Vy9V82 T cells from peripheral blood and tumor specimens of patients with EGFR thorn cancers had a distinct immune checkpoint expres-sion profile characterized by low levels of PD-1, LAG-3, and TIM-3. Vy9V82 T cells could be activated by EGFR-V82 bsTCEs to mediate lysis of various EGFR thorn patient-derived tumor samples,and substantial tumor growth inhibition and improved survival were observed in in vivo xenograft mouse models using peripheral blood mononuclear cells (PBMC) as effector cells. EGFR-V82 bsTCEs exerted preferential activity toward EGFR thorn tumor cells and induced downstream activation of CD4 thorn and CD8 thorn T cells and natural killer (NK) cells without concomitant activation of suppressive regulatory T cells observed with EGFR-CD3 bsTCEs. Administration of fully cross-reactive and half-life extended surrogate engagers to NHPs did not trigger signals in the safety parameters that were assessed. Considering the effector and immune-activating properties of Vy9V82 T cells, the preclinical efficacy data and acceptable safety profile reported here provide a solid basis for testing EGFR-V82 bsTCEs in patients with EGFR thorn malignancies. Show less
Lameris, R.; Ruben, J.M.; Iglesias-Guimarais, V.; Jong, M. de; Veth, M.; Bovenkamp, F.S. van de; ... ; Vliet, H.J. van der 2023
Bispecific T cell engagers (bsTCEs) hold great promise for cancer treatment but face challenges due to the induction of cytokine release syndrome (CRS), on-target off-tumor toxicity, and the... Show moreBispecific T cell engagers (bsTCEs) hold great promise for cancer treatment but face challenges due to the induction of cytokine release syndrome (CRS), on-target off-tumor toxicity, and the engagement of immuno-suppressive regulatory T cells that limit efficacy. The development of Vy9V52-T cell engagers may overcome these challenges by combining high therapeutic efficacy with limited toxicity. By linking a CD1d-specific single-domain antibody (VHH) to a V52-TCR-specific VHH, we create a bsTCE with trispecific properties, which engages not only Vy9V52-T cells but also type 1 NKT cells to CD1d+ tumors and triggers robust proin-flammatory cytokine production, effector cell expansion, and target cell lysis in vitro. We show that CD1d is expressed by the majority of patient MM, (myelo)monocytic AML, and CLL cells and that the bsTCE triggers type 1 NKT and Vy9V52-T cell-mediated antitumor activity against these patient tumor cells and improves survival in in vivo AML, MM, and T-ALL mouse models. Evaluation of a surrogate CD1d-y5 bsTCE in NHPs shows Vy9V52-T cell engagement and excellent tolerability. Based on these results, CD1d-V52 bsTCE (LAVA-051) is now evaluated in a phase 1/2a study in patients with therapy refractory CLL, MM, or AML. Show less
Weerdt, I. de; Lameris, R.; Ruben, J.M.; Boer, R. de; Kloosterman, J.; King, L.A.; ... ; Vliet, H.J. van der 2021
Purpose: Although considerable progress has been made with autologous T cell-based therapy in B-cell malignancies, application in chronic lymphocytic leukemia (CLL) lags behind due to disappointing... Show morePurpose: Although considerable progress has been made with autologous T cell-based therapy in B-cell malignancies, application in chronic lymphocytic leukemia (CLL) lags behind due to disappointing response rates as well as substantial toxicity that is of particular concern in the elderly CLL population. V gamma 9V delta 2-T cells form a conserved T-cell subset with strong intrinsic immunotherapeutic potential, largely because of their capacity to be triggered by phosphoantigens that can be overproduced by CLL and other malignant cells. Specific activation of V gamma 9V delta 2-T cells by a bispecific antibody may improve the efficacy and toxicity of autologous T-cell-based therapy in CLL.Experimental Design: We evaluated CD1d expression in a cohort of 78 untreated patients with CLL and generated and functionally characterized a CD1d-specific V gamma 9V delta 2-T cell engager based on single-domain antibodies (VHH).Results: CD1d was expressed by CLL in the majority of patients, particularly in patients with advanced disease. The CD1d-specific V gamma 9V delta 2-T cell engager induced robust activation and degranulation of V gamma 9V delta 2- T cells, enabling V gamma 9V delta 2-T cells from patients with CLL to lyse autologous leukemic cells at low effector-to-target ratios. Expression of CD1d on CLL cells is upregulated by all-trans retinoic acid, and sensitizes the malignant cells to bispecific VHH-induced lysis. Furthermore, we provide evidence that the V gamma 9V delta 2-T cell receptor retains responsiveness to phosphoantigens when the bispecific VHH is bound, and aminobisphosphonates can therefore enhance bispecific V gamma 9V delta 2-T cell engager-mediated tumor-specific killing.Conclusions: Collectively, our data demonstrate the immunotherapeutic potential of this novel CD1d-specific V gamma 9V delta 2-T cell engager in CLL. Show less
