Purpose: To assess the potential for CUE-101, a novel therapeutic fusion protein, to selectively activate and expand HPV16 E7 11-20-specific CD8 þ 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. Experimental Design: 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 in vivo 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. Results: CUE-101 demonstrates selective binding, activation, and expansion of HPV16 E7 11-20-specific CD8 þ T cells from PBMCs relative to nontarget cells. Intravenous administration of CUE-101 induced selective expansion of HPV16 E7 11-20-specific CD8 þ 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. Conclusions: Consistent with its design, CUE-101 demonstrates selective expansion of an HPV16 E7 11-20-specific population of cytotoxic CD8 þ T cells, a favorable safety profile, and in vitro and in vivo evidence supporting its potential for clinical efficacy in an ongoing phase I trial (NCT03978689).

Immunization and nutritional interventions are mainstays of child health programs in sub-Saharan Africa, yet few published data exist on their interactions. HIV-exposed (but uninfected) infants enrolled in a randomized placebo-controlled trial of multivitamin supplements (vitamins B complex, C, and E) conducted in Tanzania were sampled for an assessment of measles IgG quantity and avidity at 15 to 18 months. Infants were vaccinated between 8.5 and 12 months of age, and all mothers received high-dose multivitamins as the standard of care. Of 201 HIV-exposed infants who were enrolled, 138 (68.7%) were seropositive for measles. There were no effects of infant multivitamin supplementation on measles seroconversion proportions, IgG concentrations, or IgG avidity (P > 0.05). The measles seroconversion proportion was greater for HIV-exposed infants vaccinated at 10 to 11 months of age than for those vaccinated at 8.5 to 10 months (P ‫؍‬ 0.032) and greater for infants whose mothers had a CD4 T-cell count of <200 cells/l than for infants whose mothers had a CD4 T-cell count of >350 cells/l (P ‫؍‬ 0.039). Stunted infants had a significantly decreased IgG quantity compared to nonstunted infants (P ‫؍‬ 0.012). As for measles avidity, HIV-exposed infants vaccinated at 10 to 11 months had increased antibody avidity compared to those vaccinated at 8.5 to 10 months (P ‫؍‬ 0.031). Maternal CD4 T-cell counts of <200 cells/l were associated with decreased avidity compared to counts of >350 cells/l (P ‫؍‬ 0.047), as were lower infant height-for-age z-scores (P ‫؍‬ 0.016). Supplementation with multivitamins containing B complex, C, and E does not appear to improve measles vaccine responses for HIV-exposed infants. Studies are needed to better characterize the impact of maternal HIV disease severity on the immune system development of HIV-exposed infants and the effect of malnutrition interventions on vaccine responses. (This study has been registered at ClinicalTrials.gov under registration no. NCT00197730.)

BackgroundWilms' Tumor 1 (WT1) was ranked as the highest priority antigen for therapeutic targeting in an effort by the National Cancer Institute. Development of novel modalities targeting WT1 provide a significant opportunity to address high unmet medical need in WT1-positive malignancies, including AML, ovarian, endometrial, breast, lung, colorectal and pancreatic cancer. Leveraging the Immuno-STAT platform of targeted IL-2 therapies, and the ongoing development of CUE-101, CUE-102 is being developed as a novel therapeutic fusion protein to selectively activate tumor antigen-specific T cells to treat WT1-expressing cancers. CUE-102 consists of two human leukocyte antigen (HLA) molecules presenting a WT1 peptide, four affinity-attenuated human interleukin-2 (IL-2) molecules, and an effector attenuated human immunoglobulin G (IgG1) Fc domain.MethodsHuman PBMCs were tested to demonstrate cellular activity and specificity of CUE-102, while in vivo activity of CUE-102 was assessed in HLA-A2 transgenic mice. HLA-A2/WT1-specific TCRs were validated and expressed in primary human CD8 T cells. Tetramer staining and flow cytometry identified cell populations and activation markers.ResultsMultiple in vitro assessments demonstrate that CUE-102 selectively activates and expands WT1-specific CD8+ T cells from PBMC of healthy and cancer bearing donors. These CUE-102-expanded CD8+ T cells exhibit polyfunctional and cytotoxic responses upon challenge with WT1-presenting target cells. In addition, significant functional attenuation of the IL-2 components of CUE-102 was shown, similar to preclinical results obtained with CUE-101. In vivo studies in HLA-A2 transgenic mice confirm that CUE-102 elicits and expands polyfunctional WT1-specific CD8+ T cells from naïve and previously immunized mice without significantly altering the frequencies of other immune lineages. The WT1-specific CD8+ T cells expanded in vivo exhibit polyfunctionality in response to peptide-loaded target cells, and selectively kill WT1-presenting target cells in vivo.ConclusionsCUE-102 elicits selective expansion of a WT1-specific population of cytotoxic CD8+ T cells both in vitro and in vivo. These results, together with its similarity to CUE-101, support its anticipated tolerability profile and potential for clinical efficacy in a Phase 1 trial planned to initiate in 2022.Ethics ApprovalAll animal studies followed guidance from the SmartLabs Institutional Animal Care and Use Committee protocol MIL-100 and were performed in compliance with federal guidelines.

<p>Supplementary Table 1</p>