GEO-CM04S1 Demonstrates Superior T Cell Responses Compared to mRNA Vaccine in Phase 2 Trial Among Immunocompromised Patients
ATLANTA, GA - June 17, 2025 (NEWMEDIAWIRE) - GeoVax Labs, Inc. (Nasdaq: GOVX), a clinical-stage biotechnology company developing multi-antigen vaccines and immunotherapies for infectious diseases and cancer, today highlighted new clinical data presented at the 2025 European Hematology Association (EHA) Hybrid Congress, which took place June 12-15 in Milan, Italy.
The data were featured in a poster presentation by Alexey V. Danilov, M.D., Ph.D., Associate Director of the Toni Stephenson Lymphoma Center and Professor in the Department of Hematology and Hematopoietic Cell Transplantation at City of Hope Comprehensive Cancer Center in Duarte, California. The poster titled “MVA-Based GEO-CM04S1 Vaccine Results in Improved Cellular Immune Response in Patients with Chronic Lymphocytic Leukemia (CLL) Compared with mRNA-Based Vaccine: Initial Results of a Phase II Randomized Study”, detailed findings from an ongoing randomized Phase 2 clinical trial (NCT05672355), and highlighted interim results showing superior cellular immune responses induced by GEO-CM04S1 compared to those induced by an authorized mRNA-based COVID-19 vaccine in CLL patients, a population known to exhibit suboptimal protective responses to COVID-19 and other vaccines due to immune dysfunction.
Key Findings from the Study
- GEO-CM04S1 demonstrated significantly enhanced T cell responses, specifically IFN-γ secretion and activation-induced markers (AIM+), compared to a matched cohort receiving an authorized mRNA vaccine.
- While both vaccines stimulated humoral immune responses, only GEO-CM04S1 elicited statistically significant SARS-CoV-2 Nucleocapsid (N)-specific IgG and T cell responses.
- The mRNA vaccine failed to meet the pre-defined primary immunogenicity endpoint; as a result, further enrollment is now restricted to the GEO-CM04S1 arm only.
- Both vaccines were well-tolerated, with no grade ≥3 adverse events reported.
“These findings reinforce the clinical and immunologic advantages of our multi-antigen approach,” said Kelly T. McKee, Jr., M.D., Chief Medical Officer of GeoVax. “GEO-CM04S1’s robust cellular response in immunocompromised individuals, especially patients with hematologic malignancies like CLL, provides further validation of our MVA platform's potential to address critical gaps in COVID-19 protection.”
About GEO-CM04S1
GEO-CM04S1 is a next-generation COVID-19 vaccine based on a synthetic Modified Vaccinia Ankara (MVA) vector. Unlike single-antigen vaccines, it expresses both the Spike (S) and Nucleocapsid (N) proteins of SARS-CoV-2, aiming to provide broader, cross-reactive, and more durable immunity. The vaccine is currently being evaluated in three Phase 2 clinical trials across various patient populations, including immunocompromised individuals and healthy adults.
About GeoVax
GeoVax Labs, Inc. is a clinical-stage biotechnology company developing novel vaccines against infectious diseases and therapies for solid tumor cancers. The Company’s lead clinical program is GEO-CM04S1, a next-generation COVID-19 vaccine currently in three Phase 2 clinical trials, being evaluated as (1) a primary vaccine for immunocompromised patients such as those suffering from hematologic cancers and other patient populations for whom the current authorized COVID-19 vaccines are insufficient, (2) a booster vaccine in patients with chronic lymphocytic leukemia (CLL) and (3) a more robust, durable COVID-19 booster among healthy patients who previously received the mRNA vaccines. In oncology the lead clinical program is evaluating a novel oncolytic solid tumor gene-directed therapy, Gedeptin®, having recently completed a multicenter Phase 1/2 clinical trial for advanced head and neck cancers. GeoVax is also developing a vaccine targeting Mpox and smallpox and, based on recent regulatory guidance, anticipates progressing directly to a Phase 3 clinical evaluation, omitting Phase 1 and Phase 2 trials. GeoVax has a strong IP portfolio in support of its technologies and product candidates, holding worldwide rights for its technologies and products. For more information about the current status of our clinical trials and other updates, visit our website: 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.
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