GeoVax Highlights Strategic Implications of Recent Gedeptin(R) Findings for Checkpoint-Resistant Cancers

Recent Publication and Growing Industry Focus on Immune-Priming Strategies Support Continued Evaluation of Gedeptin® as a Potential Complement to Checkpoint Inhibitor Therapy

ATLANTA, GA - June 17, 2026 (NEWMEDIAWIRE) - GeoVax Labs, Inc. (Nasdaq: GOVX), a clinical-stage biotechnology company developing immunotherapies and vaccines for solid tumors and infectious diseases, today highlighted the broader oncology and strategic implications of recently published research supporting the potential of its Gedeptin® platform to enhance immune checkpoint inhibitor activity and address one of the most significant challenges in modern cancer treatment: improving responses in checkpoint-resistant tumors.

The update follows publication of the peer-reviewed article, “Broadening Activity of Checkpoint Blockade Agents by Intratumoral Nucleoside Cleavage,” in JCI Insight. The study reported findings supporting the potential for Gene-Directed Enzyme-Prodrug Therapy (GDEPT) to enhance checkpoint inhibitor responses, activate systemic anti-tumor immunity, and generate anti-tumor effects in both treated and distant untreated tumors in preclinical models of checkpoint-resistant triple-negative breast cancer.

While the publication focused on the underlying scientific findings, GeoVax views the results as further validation of broader trends shaping the future of cancer immunotherapy, including increasing industry emphasis on immune-priming approaches designed to improve checkpoint inhibitor responsiveness and overcome treatment resistance.

Addressing the Challenge of Checkpoint Resistance

Checkpoint inhibitors targeting pathways, such as PD-1 and PD-L1, have transformed treatment paradigms across multiple cancer types and now represent foundational therapies in modern oncology. Despite their success, many tumors remain poorly responsive to checkpoint blockade due to limited immune-cell infiltration, poor antigen presentation, and immunosuppressive tumor microenvironments.

These so-called “cold” tumors represent one of the most significant barriers to effective immunotherapy. Without sufficient immune recognition and engagement, even highly active therapies may struggle to generate durable clinical responses.

GeoVax recently explored this challenge in an Onco'Zine commentary authored by Chairman and Chief Executive Officer David Dodd entitled, “The Cold Tumor Barrier: Why Promising Oncology Therapies Fail In Vivo – and What It Will Take to Overcome It”. The article discussed the growing recognition that future advances in immuno-oncology may depend not only on developing new therapies, but also on improving the responsiveness of tumors to existing treatments through immune activation and tumor microenvironment modulation.

As a result, substantial research and development efforts across the oncology sector are increasingly focused on identifying therapies capable of converting immunologically cold tumors into more responsive tumors, potentially expanding the number of patients who may benefit from immunotherapy and improving outcomes with established checkpoint inhibitor regimens.

“One of the most significant challenges in oncology today is the cold tumor barrier,” said David Dodd, Chairman and Chief Executive Officer of GeoVax. “Checkpoint inhibitors can be highly effective when sufficient immune activity already exists within a tumor. However, many tumors remain largely invisible to the immune system. The next major opportunity may lie in therapies capable of activating immune recognition and making these tumors more responsive to existing immunotherapies.”

Positioning Gedeptin Within an Emerging Immunotherapy Paradigm

GeoVax sees potential for Gedeptin to play a differentiated role within this evolving treatment landscape. The recently published findings suggest that localized treatment may not only destroy targeted tumor cells, but also remodel the tumor microenvironment, promote immune activation, and enhance responsiveness to checkpoint inhibitors. These characteristics are increasingly viewed as important components of next-generation combination immunotherapy strategies.

The Company views Gedeptin's combination of localized tumor destruction, strong bystander killing effects, tumor microenvironment remodeling, and immune activation as a potentially differentiated approach to addressing treatment resistance.

“Importantly, Gedeptin is not necessarily intended to directly compete with checkpoint inhibitors, but rather to complement them,” continued Mr. Dodd. “The medical proposition is to improve responses where checkpoint inhibitors alone have not achieved their full potential; also representing a significant commercial opportunity with multiple partnering avenues.”

Focus on Neoadjuvant Combination Strategies

GeoVax's lead clinical development focus for Gedeptin is a planned neoadjuvant study in recurrent head and neck squamous cell carcinoma (HNSCC), evaluating intratumoral Gedeptin in combination with PD-1-based immunotherapy and standard of care, in patients with first recurrent Head and Neck Squamous Cell Carcinoma (HNSCC) eligible for curative-intent surgery.

The Company considers recurrent head and neck cancer an attractive initial development setting because tumors are frequently accessible for direct injection, checkpoint inhibitors are already integrated into standard of care treatment paradigms, and substantial unmet need remains despite advances in immunotherapy.

GeoVax also views the neoadjuvant setting as particularly well suited for immune-priming approaches because the intact tumor can serve as a source of tumor antigens capable of stimulating broader anti-tumor immune responses prior to surgical resection.

“As checkpoint inhibitors continue moving earlier in the treatment paradigm, opportunities are emerging for therapies designed to improve immune responsiveness before surgery and potentially improve long-term outcomes,” said Mr. Dodd. “Gedeptin's biologic profile appears well aligned with this evolving treatment strategy.”

Broader Platform Opportunities

Beyond head and neck cancer, GeoVax sees potential applicability for Gedeptin across multiple solid tumor settings where checkpoint inhibitors are established standard of care but response rates remain suboptimal.

“The oncology community is increasingly focused on improving response rates to existing immunotherapies and overcoming the cold tumor barrier,” added Mr. Dodd. “The emerging data support continued evaluation of Gedeptin as a differentiated immune-priming platform designed to complement existing immunotherapies and potentially broaden the impact of checkpoint blockade across multiple tumor settings.”

About Gedeptin®

Gedeptin® is GeoVax's proprietary gene-directed enzyme prodrug therapy (GDEPT) platform under development for the treatment of solid tumors. The therapy utilizes a non-replicating adenoviral vector encoding purine nucleoside phosphorylase (PNP). Following administration of fludarabine, the PNP enzyme converts the prodrug into a potent localized cytotoxic compound within the tumor microenvironment.

GeoVax is advancing development plans evaluating Gedeptin in combination with checkpoint inhibitors, including pembrolizumab-based regimens, with the goal of improving anti-tumor immune responsiveness across multiple solid tumor indications.

About GeoVax

GeoVax Labs, Inc. is a clinical-stage biotechnology company focused on the development of vaccines and immunotherapies addressing high-consequence infectious diseases and solid tumor cancers. GeoVax’s priority program is GEO-MVA, a Modified Vaccinia Ankara (MVA)–based vaccine targeting mpox and smallpox. The program is advancing under an expedited regulatory pathway, with plans to initiate a pivotal Phase 3 clinical trial in the second half of 2026, to address critical global needs for expanded orthopoxvirus vaccine supply and biodefense preparedness. In oncology, GeoVax is developing Gedeptin®, a gene-directed enzyme prodrug therapy (GDEPT) designed to enhance immune checkpoint inhibitor activity. Gedeptin has completed a multicenter Phase 1/2 clinical trial in advanced head and neck cancer and is being advanced into combination strategies, including planned neoadjuvant and first-line settings. GeoVax maintains a global intellectual property portfolio supporting its infectious disease and oncology programs and continues to evaluate strategic partnerships and funding opportunities aligned with its development priorities. For more information, visit www.geovax.com.

Forward-Looking Statements

This release contains forward-looking statements regarding GeoVax’s business plans. The words “believe,” “look forward to,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “could,” “target,” “potential,” “is likely,” “will,” “expect” and similar expressions, as they relate to us, are intended to identify forward-looking statements. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our financial condition, results of operations, business strategy and financial needs. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: GeoVax is able to obtain acceptable results from ongoing or future clinical trials of its investigational products, GeoVax’s immuno-oncology products and preventative vaccines can provoke the desired responses, and those products or vaccines can be used effectively, GeoVax’s viral vector technology adequately amplifies immune responses to cancer antigens, GeoVax can develop and manufacture its immuno-oncology products and preventative vaccines with the desired characteristics in a timely manner, GeoVax’s immuno-oncology products and preventative vaccines will be safe for human use, GeoVax’s vaccines will effectively prevent targeted infections in humans, GeoVax’s immuno-oncology products and preventative vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete development, there is development of competitive products that may be more effective or easier to use than GeoVax’s products, GeoVax will be able to enter into favorable manufacturing and distribution agreements, and other factors, over which GeoVax has no control.

Further information on our risk factors is contained in our periodic reports on Form 10-Q and Form 10-K that we have filed and will file with the SEC. Any forward-looking statement made by us herein speaks only as of the date on which it is made. Factors or events that could cause our actual results to differ may emerge from time to time, and it is not possible for us to predict all of them. We undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future developments or otherwise, except as may be required by law.

Company Contact:
info@geovax.com
678-384-7220

Media Contact:
Jessica Starman
media@geovax.com 

News Source: GeoVax, Inc.