Development and Characterization of A Bi-Specific Antibody Targeting Hla-A2/Pr1

<p>Despite substantial advances in the treatment of acute myeloid leukemia (AML), only 30% of AML patients survive more than 5 years. Therefore, new therapeutics are much needed. Here, we present novel therapeutic strategy targeting myeloid leukemia antigen, HLA-A2 restricted peptide PR1.Previously, we have conducted pre-clinical development and humanization of a T cell receptor-like monoclonal antibody (h8F4) that targets PR1/HLA-A2 and eliminates AML xenografts by antibody-dependent cellular cytotoxicity (ADCC) following repeat dosing. To improve the potency of h8F4, we have developed a bi-specific T cell-engaging antibody that targets PR1/HLA-A2 on leukemia and CD3 on neighboring T cells. Here we demonstrate successful production and purification of the h8F4 bi-specific antibody. Utilizing flow cytometry, we confirm PR1/HLA-A2 and CD3-specific binding characteristics, T cell activation in the presence of PR1/HLA-A2, and importantly AML target cell cytotoxicity after h8F4 bi-specific antibody engagement with healthy donor effector T cells. Cytotoxicity assays were performed with both AML cell lines and primary patient AML blasts serving as target cells and health donor PBMC as a source of effector T cells at an Effector: Target ratio of 2:1. Results indicate up to 50% leukemia-specific lysis with 0.2nM h8F4 bi-specific antibody after only 18 hours of incubation. In addition, <em>in vivo </em>data also confirms significant elimination of the leukemia cell line U937 (as evidenced by % leukemia cells detected in peripheral blood and bio-luminescence imaging) in an NSG-U937 AML xenograft mouse model when compared to control groups treated with effector cells alone. In conclusion, these studies demonstrate the therapeutic potential of a novel bi-specific antibody targeting the PR1/HLA-A2 leukemia-associated antigen. This bi-specific antibody appears to increase the potency of h8F4 with rapid elimination of AML and our studies justify potential development as a treatment option for patients with high-risk AML.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation (PhD)

Year dc:date.available

2018

Authors dc:creator

• Herrmann, Amanda
• <p>https://orcid.org/0000-0002-3912-5068</p>

Contributors dc:contributor

• Jeffrey Molldrem MD
• Gheath Al-Atrash DO, PhD
• William Plunkett PhD

• Acute Myeloid Leukemia
• bi-specific antibody
• cancer immunotherapy
• re-directed cytotoxicity
• Medicine and Health Sciences

Repository record dc:identifier

https://digitalcommons.library.tmc.edu/utgsbs_dissertations/853

OAI identifier oai:identifier

oai:digitalcommons.library.tmc.edu:utgsbs_dissertations-1899