GeoVax Commences Site Expansion for Phase 2 Trial of Next-Generation COVID-19 Vaccine

Designed to Protect Immunocompromised Patients Against Severe COVID-19

ATLANTA, GA, October 30, 2023 – GeoVax Labs, Inc. (Nasdaq: GOVX), a biotechnology company developing immunotherapies and vaccines against cancers and infectious diseases, today announced that it has commenced the planned site expansion for the Phase 2 clinical trial investigating its next-generation SARS-CoV-2 vaccine, GEO-CM04S1, as a primary vaccine in immunocompromised patients.  In addition to study enrollments completed at the City of Hope Medical Center (Duarte, California), the trial will be initiating enrollment of eligible patients at Wake Forest Baptist Medical Center (Winston Salem, North Carolina), the University of Massachusetts Medical Center (Worcester, Massachusetts), and Fred Hutchinson Cancer Research Center (Seattle, Washington).

The Phase 2 clinical trial ( Identifier: NCT04977024) is evaluating the safety and immunogenicity of GEO-CM04S1, compared to either the Pfizer/BioNTech or Moderna mRNA-based vaccine, in patients with hematologic malignancies who have received either an allogeneic hematopoietic stem cell transplant, an autologous hematopoietic stem cell transplant or chimeric antigen receptor (CAR) T cell therapy. Such patients often have difficulty mounting an adequate protective antibody response after receiving currently available COVID-19 vaccines.

David Dodd, GeoVax Chairman and CEO, commented, “We are pleased with these site activations to expand the scope and reach of this trial, which we expect will accelerate patient enrollment for this important study in one of the highest at-risk patient populations, currently underserved by available vaccines. We believe the unique properties of GEO-CM04S1 potentially offer a more robust, durable degree of protection than the current authorized COVID-19 vaccines, not only as a vaccine for highly vulnerable immunocompromised patients for whom the currently authorized mRNA vaccines may be inadequate, but also potentially for healthy patients as a universal booster vaccine to the mRNA vaccines.  In the U.S., there are approximately 15 million individuals who, as a result of their compromised immune systems, often do not adequately respond to the current authorized vaccines.  Worldwide, there are an estimated 240+ million such patients. Our hope is that GEO-CM04S1 provides robust, durable immune protection for such patients, while also providing a critically important alternative to COVID-19 booster vaccines for healthy individuals.”

A recent publication in Vaccines ( from the open-label portion of the trial indicates that GEO-CM04S1 is highly immunogenic in these patients, inducing both antibody responses, including neutralizing antibodies, and T cell responses against ancestral as well as recently evolved SARS-CoV-2 virus strains. These data support the progression of the Phase 2 clinical study, which includes a direct comparison to currently approved mRNA vaccines.

About GEO-CM04S1

GEO-CM04S1 is based on GeoVax’s MVA viral vector platform, which supports the presentation of multiple vaccine antigens to the immune system in a single dose. GEO-CM04S1 encodes for both the spike (S) and nucleocapsid (N) antigens of SARS-CoV-2 and is specifically designed to induce both antibody and T cell responses to those parts of the virus less likely to mutate over time. The more broadly functional engagement of the immune system is designed to protect against severe disease caused by continually emerging variants of COVID-19. Vaccines of this format should not require frequent and repeated modification or updating.

In addition to this ongoing study, GEO-CM04S1 is being evaluated in two other Phase 2 clinical trials:

  • As a booster vaccine for healthy patients who have previously received the Pfizer or Moderna mRNA vaccine. Identifier: NCT04639466.  GeoVax recently announced that this trial has fully enrolled.
  • As a booster vaccine in immunocompromised patients with chronic lymphocytic leukemia (CLL), a recognized high-risk group for whom current mRNA vaccines and monoclonal antibody (MAb) therapies appear inadequate relative to providing protective immunity. Identifier: NCT05672355.

About GeoVax

GeoVax Labs, Inc. is a clinical-stage biotechnology company developing novel therapies and vaccines for solid tumor cancers and many of the world’s most threatening infectious diseases. The company’s lead program in oncology is a novel oncolytic solid tumor gene-directed therapy, Gedeptin®, presently in a multicenter Phase 1/2 clinical trial for advanced head and neck cancers. GeoVax’s lead infectious disease candidate is GEO-CM04S1, a next-generation COVID-19 vaccine targeting high-risk immunocompromised patient populations. Currently in three Phase 2 clinical trials, GEO-CM04S1 is being evaluated as 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, and as a booster vaccine in patients with chronic lymphocytic leukemia (CLL). In addition, GEO-CM04S1 is in a Phase 2 clinical trial evaluating the vaccine as a more robust, durable COVID-19 booster among healthy patients who previously received the mRNA vaccines. GeoVax has a leadership team who have driven significant value creation across multiple life science companies over the past several decades. For more information, visit our website:

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