Date of Award

January 2025

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Michael Girardi

Abstract

Cutaneous T-cell lymphoma (CTCL) is a non-Hodgkin lymphoma characterized as a malignancy of T-cells that variably involves the skin, lymph nodes, and blood. Many therapeutic options exist for patients with CTCL, ranging from narrow-band UVB, extracorporeal photopheresis, total skin electron beam therapy, retinoids, histone deacetylase inhibitors, antibody drug conjugates, and chimeric antigen receptor (CAR) T-cell therapy. Despite the various advances in treatment options, these therapies are non-curative with overall response rates ranging from 30 to 55%, warranting the need for better alternatives that also aim to reduce toxic systemic effects. Project 1: Prior work in a series of publications by the Girardi Lab demonstrated the therapeutic potential for CTCL of novel combinations of Janus kinase (JAK) inhibitors, proteasome inhibitors, B-cell leukemia/lymphoma 2 protein inhibitors, histone deacetylase inhibitors, and bromodomain and extra-terminal motif inhibitors. Furthermore, other investigators have shown the advantageous potential of proteolysis targeting chimeras (PROTACs) in creating a therapeutic approach that more specifically degrades proteins of interest while lessening overall toxicity. Through this work we aimed to determine efficacy of four novel and proprietary JAK-targeting PROTAC agents to selectively destroy malignant CTCL cells derived from Sézary patients. A drug screen was conducted utilizing peripheral blood samples from 8 CTCL patients to determine the efficacy of four novel JAK-targeting PROTAC agents, which were uniquely designed to be undergo hydrolysis upon bloodstream entry, resulting in a therapeutic that could be more skin-specific. All four novel JAK-targeting PROTACs demonstrated efficacy in selective destruction of malignant CTCL cells, when compared to a known JAK-inhibitor control, fedratinib. The success of these novel therapeutics demonstrate hope for a more skin-targeted treatment that would degrade upon entry to the blood, reducing overall toxicity. Project 2: Furthermore, recent work in the Girardi Lab has created an off-the-shelf allogeneic chimeric antigen receptor (CAR)-T platform targeting the clone-specific T-cell receptor (TCR) Vβ2 chain for malignant T-cell killing while limiting non-malignant cell damage at levels not currently available. Girardi Lab has also produced a humanized anti-Vβ2 IgG1 antibody, with Fc-engineering to enhanced antibody dependent-cellular cytotoxicity (ADCC). Through this work, we aimed to determine the efficacy of this humanized anti-Vβ2 IgG1 antibody to reduce tumor burden in a preclinical patient derived xenograft (PDX) mouse model of CTCL which was measured using long-term bioluminescence imaging and flow cytometry to determine tumor burden. The bioluminescence imaging results demonstrated reduced tumor burden when used alone and in combination with natural killer cells. Furthermore, flow cytometry demonstrated the bone marrow of treated mice had a reduced absolute tumor cell count. Both of these personalized therapeutic approaches demonstrate promising treatment options that would offer more targeted approaches against malignant cells and therefore would be predicted to reduce overall toxicity. Furthermore, the preclinical assessment of these agents selectively targeting populations of activated T-cells suggests that these therapeutics could one day be utilized for other skin diseases driven by inflammatory T-cells, such as such as atopic dermatitis, psoriasis, graft vs. host disease, lichen planus, vitiligo, and alopecia areata. Further investigation in additional models beyond patient derived malignant cells and mouse models are warranted to determine generalizability and efficacy.

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This is an Open Access Thesis.

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