CUE-101, a Novel E7-pHLA-IL2-Fc Fusion Protein, Enhances Tumor Antigen-Specific T-Cell Activation for the Treatment of HPV16-Driven Malignancies.

Abstract

To assess the potential for CUE-101, a novel therapeutic fusion protein, to selectively activate and expand HPV16 E7_11-20-specific CD8⁺ T cells as an off-the shelf therapy for the treatment of HPV16-driven tumors, including head and neck squamous cell carcinoma (HNSCC), cervical, and anal cancers. CUE-101 is an Fc fusion protein composed of a human leukocyte antigen (HLA) complex, an HPV16 E7 peptide epitope, reduced affinity human IL2 molecules, and an effector attenuated human IgG1 Fc domain. Human E7-specific T cells and human peripheral blood mononuclear cells (PBMC) were tested to demonstrate cellular activity and specificity of CUE-101, whereas <i>in vivo</i> activity of CUE-101 was assessed in HLA-A2 transgenic mice. Antitumor efficacy with a murine surrogate (mCUE-101) was tested in the TC-1 syngeneic tumor model. CUE-101 demonstrates selective binding, activation, and expansion of HPV16 E7_11-20-specific CD8⁺ T cells from PBMCs relative to nontarget cells. Intravenous administration of CUE-101 induced selective expansion of HPV16 E7_11-20-specific CD8⁺ T cells in HLA-A2 (AAD) transgenic mice, and anticancer efficacy and immunologic memory was demonstrated in TC-1 tumor-bearing mice treated with mCUE-101. Combination therapy with anti-PD-1 checkpoint blockade further enhanced the observed efficacy. Consistent with its design, CUE-101 demonstrates selective expansion of an HPV16 E7_11-20-specific population of cytotoxic CD8⁺ T cells, a favorable safety profile, and <i>in vitro</i> and <i>in vivo</i> evidence supporting its potential for clinical efficacy in an ongoing phase I trial (NCT03978689).