King et al. generated an EGFR-Vδ2 bispecific T cell engager (EGFR-Vδ2 bsTCEs) that activated Vγ9Vδ2 T cells from PBMC and tumor samples to selectively kill EGFR+ tumor cells, and assessed its antitumor activity and safety profiles. In patients with cancer, Vγ9Vδ2 T cells showed a shift toward effector phenotypes, with low levels of PD-1, LAG-3, and TIM-3 expression. EGFR-Vδ2 bsTCE-activated Vγ9Vδ2 T cells induced IFNγ- and TNF-mediated downstream activation of T and NK cells, suppressed tumor growth, and improved survival in xenograft models. Tregs were not induced. A surrogate EGFR-Vγ9 bsTCE showed no signs of toxicity, despite target engagement in NHPs.

Contributed by Shishir Pant

ABSTRACT: Vγ9Vδ2 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 Vγ9Vδ2 T cells to EGFR-expressing tumors. An EGFR-Vδ2 bispecific T-cell engager (bsTCE) was generated and its capacity to activate Vγ9Vδ2 T cells and trigger antitumor activity were tested in multiple in vitro, in vivo, and ex vivo models. Studies to explore safety were conducted using cross-reactive surrogate engagers in non-human primates (NHP). We found that Vγ9Vδ2 T cells from peripheral blood and tumor specimens of patients with EGFR+ cancers had a distinct immune checkpoint expression profile characterized by low levels of PD-1, LAG-3, and TIM-3. Vγ9Vδ2 T cells could be activated by EGFR-Vδ2 bsTCEs to mediate lysis of various EGFR+ patient-derived tumor samples and substantial tumor growth inhibition and improved survival were observed in in vivo xenograft mouse models using PBMCs as effector cells. EGFR-Vδ2 bsTCEs exerted preferential activity towards EGFR+ tumor cells and induced downstream activation of CD4+ and CD8+ T cells and 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 Vγ9Vδ2 T cells, the preclinical efficacy data and acceptable safety profile reported here provide a solid basis for testing EGFR-Vδ2 bsTCEs in patients with EGFR+ malignancies.

Author Info: (1) Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands. (2) Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands. (3) Amsterdam UMC, Vrije Universiteit, Amsterdam, Neth

Author Info: (1) Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands. (2) Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands. (3) Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands. (4) Lava Therapeutics NV, Utrecht, Netherlands. (5) Sanquin Research/Landsteiner laboratory AMC, Amsterdam, Netherlands. (6) Sanquin Research/Landsteiner laboratory AMC, Amsterdam, Amsterdam, Netherlands. (7) Amsterdam UMC Location VUmc, Amsterdam, Netherlands. (8) Amsterdam UMC, location VUMC, Cancer Center Amsterdam, Amsterdam UMC, Amsterdam, MA, Netherlands. (9) Amsterdam UMC Location VUmc, Amsterdam, Netherlands. (10) Amsterdam UMC, Amsterdam, Netherlands. (11) Lava Therapeutics NV, Utrecht, Netherlands. (12) Lava Therapeutics NV, Utrecht, Utrecht, Netherlands. (13) Lava Therapeutics N.V., Utrecht, Utrecht, Netherlands. (14) Lava Therapeutics, Amsterdam, Netherlands. (15) Lava Therapeutics, Utrecht, Netherlands. (16) Amsterdam UMC Location VUmc, Amsterdam, Netherlands. (17) Amsterdam UMC Location VUmc, Amsterdam, Netherlands.