Coya Therapeutics’ COYA 303 Shows Promising Central Nervous System (CNS) Anti-inflammatory Effects and Systemic Regulatory T Cell (Treg) Enhancing Effects in a Preclinical Animal Inflammation Model

COYA 303 is an investigational proprietary combination of LD-IL-2 and GLP-1RA for subcutaneous administration, under development for the treatment of diseases, including Alzheimer’s Disease, driven by chronic and sustained inflammation;

COYA 303 demonstrated significant attenuation of neuroinflammation in cortex and hippocampus brain regions and upregulation of anti-inflammatory markers, and significant improvement of systemic Treg function and pro-inflammatory cytokines;

Results from the first cohort of this in-vivo animal study confirm the previously reported positive findings from in vitro human immune cell systems demonstrating that COYA 303 significantly enhances Treg suppressive function and survival in highly inflammatory microenvironments.

HOUSTON, Sept. 16, 2025 /PRNewswire/ — Coya Therapeutics, Inc. (NASDAQ: COYA) (“Coya” or the “Company”), a clinical-stage biotechnology company developing biologics intended to enhance regulatory T cell (Treg) function, today announced results of a study designed to evaluate the effects of COYA 303 (LD IL-2 and GLP-1RA), Coya’s investigational biologic combination in an established in vivo lipopolysaccharide (LPS) mouse model of systemic and neuroinflammation. Results from the first animal cohort treated with COYA 303 demonstrated broad systemic and central immunomodulatory activity, including significant reductions in LPS-induced pro-inflammatory myeloid cells and associated cytokines, increases in anti-inflammatory immune cell subsets, and attenuation of neuroinflammation in the brain, compared to untreated animals.

The Company believes these findings illustrate the potential of COYA 303 to modulate the inflammatory pathways implicated in Alzheimer’s Disease progression and support the continued development of COYA 303 in neurodegenerative conditions where persistent inflammation is a central driver of pathology.

Experimental cohorts 2 and 3 are underway and are designed to assess modified treatment protocols, specifically evaluating the impact of treatment initiation timing relative to the onset of inflammation. Upon completion of the full data set, Coya intends to present and/or publish the findings in a peer-reviewed forum.

Dr. Arun Swaminathan, Coya’s Chief Executive Officer, stated “We are encouraged by the positive signal in Cohort 1. These data are particularly timely given the increasing recognition of GLP-1 receptor agonists as potential therapies beyond metabolic disease. The upcoming semaglutide readout in Alzheimer’s Disease has generated strong interest, and we believe our unique approach of  combining LD IL-2 with a GLP-1RA in COYA 303 may leverage both Treg enhancement and myeloid modulation to address the systemic and neuroinflammatory drivers of neurodegeneration.”

LD IL-2 preferentially binds the IL-2 receptor alpha which is highly expressed on Tregs and plays a key role in enhancing Tregs’ anti-inflammatory function. Treg dysfunction is implicated in autoimmune and neurodegenerative diseases characterized by persistent inflammation. GLP-1 receptor agonists (GLP-1RAs) also module immune responses, with both myeloid cells and Tregs expressing a high density of GLP-1 receptors. Our prior in vitro studies showed that combining LD IL-2 with a GLP-1RA synergistically enhances Treg numbers and function and reduces pro-inflammatory activity. The Company believes COYA 303 builds on these findings in a validated in vivo model, potentially delivering synergistic and durable anti-inflammatory effects. Highlights from Cohort 1:

• COYA 303 produced significant systemic and CNS immunomodulatory effects in the LPS model of inflammation
• COYA 303 significantly (a) enhanced Treg numbers and suppressive function, (b) reduced peripheral activated myeloid cells and (c) attenuated neuroinflammation in the cortex and hippocampus

About Coya Therapeutics, Inc.
Headquartered in Houston, TX, Coya Therapeutics, Inc. (Nasdaq: COYA) is a clinical-stage biotechnology company developing proprietary treatments focused on the biology and potential therapeutic advantages of regulatory T cells (“Tregs”) to target systemic inflammation and neuroinflammation. Dysfunctional Tregs underlie numerous conditions, including neurodegenerative, metabolic, and autoimmune diseases, and this cellular dysfunction may lead to sustained inflammation and oxidative stress resulting in lack of homeostasis of the immune system.

Coya’s investigational product candidate pipeline leverages multiple therapeutic modalities aimed at restoring the anti-inflammatory and immunomodulatory functions of Tregs. Coya’s therapeutic platforms include Treg-enhancing biologics, Treg-derived exosomes, and autologous Treg cell therapy.

For more information about Coya, please visit www.coyatherapeutics.com

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SOURCE Coya Therapeutics, Inc.