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

Forward-Looking Statements
This press release contains "forward-looking" statements that are based on our management's beliefs and assumptions and on information currently available to management. Forward-looking statements include all statements other than statements of historical fact contained in this presentation, including information concerning our current and future financial performance, business plans and objectives, current and future clinical and preclinical development activities, timing and success of our ongoing and planned clinical trials and related data, the timing of announcements, updates and results of our clinical trials and related data, our ability to obtain and maintain regulatory approval, the potential therapeutic benefits and economic value of our product candidates, competitive position, industry environment and potential market opportunities. The words "believe," "may," "will," "estimate," "continue," "anticipate," "intend," "expect," and similar expressions are intended to identify forward-looking statements.

Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors including, but not limited to, those related to risks associated with the success, cost and timing of our product candidate development activities and ongoing and planned clinical trials; our plans to develop and commercialize targeted therapeutics; the progress of patient enrollment and dosing in our preclinical or clinical trials; the ability of our product candidates to achieve applicable endpoints in the clinical trials; the safety profile of our product candidates; the potential for data from our clinical trials to support a marketing application, as well as the timing of these events; our ability to obtain funding for our operations; development and commercialization of our product candidates; the timing of and our ability to obtain and maintain regulatory approvals; the rate and degree of market acceptance and clinical utility of our product candidates; the size and growth potential of the markets for our product candidates, and our ability to serve those markets; our commercialization, marketing and manufacturing capabilities and strategy; future agreements with third parties in connection with the commercialization of our product candidates; our expectations regarding our ability to obtain and maintain intellectual property protection; our dependence on third party manufacturers; the success of competing therapies or products that are or may become available; our ability to attract and retain key scientific or management personnel; our ability to identify additional product candidates with significant commercial potential consistent with our commercial objectives; ; and our estimates regarding expenses, future revenue, capital requirements and needs for additional financing.

We have based these forward-looking statements largely on our current expectations and projections about future events and trends that we believe may affect our financial condition, results of operations, business strategy, short-term and long-term business operations and objectives, and financial needs. Moreover, we operate in a very competitive and rapidly changing environment, and new risks may emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed herein may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements. Although our management believes that the expectations reflected in our forward-looking statements are reasonable, we cannot guarantee that the future results, levels of activity, performance or events and circumstances described in the forward-looking statements will be achieved or occur. We undertake no obligation to publicly update any forward-looking statements, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

Investor Contact 
David Snyder, CFO
[email protected]

astr partners
Matthew Beck
[email protected]
917-415-1750

Media Contacts
Russo Partners
Olipriya Das
[email protected]
646-942-5588
Matthew Purcell
[email protected]
646-942-5595

SOURCE Coya Therapeutics, Inc.