GeoVax's Multi-Antigen COVID-19 Vaccine Shows Strong Immune Response in Immunocompromised Patients

GeoVax Labs, Inc. discussed positive interim clinical results for its lead COVID-19 vaccine candidate, GEO-CM04S1, presented at the 6th ESCMID Conference on Vaccines in Lisbon, Portugal. The data highlighted encouraging immune response findings from ongoing Phase 2 clinical studies in immunocompromised patients with blood cancers and chronic lymphocytic leukemia.

No serious adverse events were attributed to GEO-CM04S1, reinforcing confidence in the platform. The vaccine demonstrated potent, durable T-cell and cross-variant antibody responses in blood cancer and post-transplant patients - immune responses that exceed those of standard-of-care vaccines. In the CLL trial interim analysis, GEO-CM04S1 met its primary endpoint, while the comparator mRNA vaccine did not, prompting continuation solely in the GEO-CM04S1 arm.

GEO-CM04S1 is a next-generation COVID-19 vaccine based on a Modified Vaccinia Ankara vector that expresses both the Spike and Nucleocapsid proteins of SARS-CoV-2, designed to stimulate robust humoral and cellular immunity. Clinical studies to date demonstrate durable immune responses and cross-variant protection, including activity against Omicron subvariants such as XBB.1.5. An updated construct incorporating the Omicron KP.2 Spike gene is slated for a 2026 trial, positioning GeoVax at the forefront of next-generation, multi-antigen COVID-19 vaccines.

David Dodd, Chairman & CEO of GeoVax, stated that these results underscore the value and competitive advantage of their multi-antigen MVA vaccine platform. The company believes GEO-CM04S1 can address urgent unmet needs among immunocompromised patients, a market segment underserved by first-generation COVID-19 vaccines. COVID-19 continues to pose a significant threat to immunocompromised patients, representing a multi-billion-dollar global market where first-generation vaccines have limited value.

GEO-CM04S1 is currently in three Phase 2 clinical trials: as a primary vaccine for immunocompromised patients with blood cancers or post-transplant status, as a booster in patients with chronic lymphocytic leukemia, and as a booster in healthy adults previously vaccinated with mRNA vaccines. For more information, visit https://www.geovax.com.

The progress being made reinforces GeoVax's potential to deliver differentiated, high-value vaccine solutions while providing platform validation for broader applications across infectious diseases. This development represents a significant advancement in protecting vulnerable populations who remain at high risk despite existing vaccination options.