Abstract 3519: EVOLVE104, a differentiated T cell engager targeting the novel antigen ULBP2/5/6, exhibits potent preclinical efficacy for the treatment of squamous tumors
Authors: Oksana A. Sergeeva, Jennifer Zeiger, Colleen Brown, William DeMaria, Donal Ryan, Antonio Ward, Guixian Jin, Martin Preyer, Yanhuai Ding, Bruce Andrien, Mark Aimone, Agnes Meade, Jay S. Fine, Jeremy S. Myers, Stella Martomo
Journal: Cancer Research (2025)

Abstract EVOLVE104 is the first CD3 T cell engager (TCE) being developed for solid tumors which utilizes integrated CD2 T cell co-stimulation. EVOLVE104 is a trispecific molecule which targets ULBP2/5/6 on the tumor cell and uses affinity-tuned CD3 engagement together with a CD2-selective fusion protein to deliver coordinated costimulatory signal integration to the T cell to optimize its effector function. ULBP2/5/6 are closely related proteins of the UL16 binding protein family which are recognized by the NKG2D receptor and induced on tumor cells while maintaining restricted expression on normal human tissues. In patient tumor samples, at both the RNA and protein level, ULBP2/5/6 expression is higher in carcinomas of squamous pathology as compared to adenocarcinomas. For example, squamous non-small cell lung cancer (NSCLC), squamous head and neck, and squamous urothelial cancer demonstrate &amp;gt; 70% ULBP2/5/6 positivity. In addition, transitional urothelial cancer, which encompasses most bladder cancers, also shows 70% ULBP2/5/6 positivity. We have verified that matched primary and metastatic urothelial, head and neck, and NSCLC tumors retain ULBP2/5/6 expression, and that standard of care treatments as late as post-third line do not decrease ULBP2/5/6 expression levels. These observations support the positioning of EVOLVE104 in squamous tumors and transitional urothelial cancers in initial clinical trials. Using a variety of indication-specific tumor cell lines, we show an in vitro T-cell directed cell cytotoxicity EC50 of ∼100 pM for EVOLVE104 with concomitant T cell activation, proliferation, and cytokine release. EVOLVE104 demonstrates a minimal efficacious dose of 0.25 mg/kg in indication-specific human cell line derived in vivo xenograft models in NSG mice engrafted with human PBMCs. In non-human primates, EVOLVE104 was well tolerated at doses up to 24 mg/kg, with no adverse findings or organ-specific toxicities at supra-pharmacologic levels compared to predicted human efficacious exposures. We show binding of EVOLVE104 in vivo on more than 95% of peripheral T cells for at least 168 hours post dose and no evidence for cytokine excursions throughout the duration of the study. Thus, preclinical data demonstrate safety and efficacy of EVOLVE104 and support the upcoming Phase I clinical study. EVOLVE104, a trispecific TCE with integrated affinity-tuned CD3 binding and CD2 co-stimulation, optimizes effector T cells for anti-tumor activity. The enriched expression of its tumor antigen target, ULBP2/5/6, in primary and metastatic squamous tumors and transitional bladder cancers, together with its compelling in vitro and in vivo pharmacology and nonclinical safety profile, position EVOLVE104 as a first-in-category immunotherapy to address underserved patient populations with high unmet needs. Citation Format: Oksana A. Sergeeva, Jennifer Zeiger, Colleen Brown, William DeMaria, Donal Ryan, Antonio Ward, Guixian Jin, Martin Preyer, Yanhuai Ding, Bruce Andrien, Mark Aimone, Agnes Meade, Jay S. Fine, Jeremy S. Myers, Stella Martomo. EVOLVE104, a differentiated T cell engager targeting the novel antigen ULBP2/5/6, exhibits potent preclinical efficacy for the treatment of squamous tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3519.