Data published in a Lancet journal on COH04S1, a City of Hope-developed COVID-19 vaccine, shows it produced robust antibodies and T cells against SARS-CoV-2

LOS ANGELES and ATLANTA — A COVID-19 investigational vaccine, developed by City of Hope scientists and now licensed to GeoVax Labs Inc. (Nasdaq: GOVX), produced a robust neutralizing antibody and T cell (an immune cell) response against SARS-CoV-2 with no significant side effects in a Phase 1 clinical trial led by John Zaia, M.D., Aaron D. Miller and Edith Miller Chair for Gene Therapy, according to a study published today in The Lancet Microbe.

COH04S1 is uniquely different than the many vaccines that have been developed because it targets both the spike and nucleocapsid proteins, in contrast to the current U.S. Food and Drug Administration (FDA)-approved COVID-19 vaccines, which only target the spike protein.

COH04S1 is being studied in a first-of-its-kind Phase 2 clinical trial for immunocompromised cancer patients who have difficulty producing antibodies and largely depend on T cells to protect against the virus responsible for COVID-19. Likewise, COH04S1 is also being evaluated in a Phase 2 vaccine booster trial format, which is aimed at evaluating how COH04S1 can boost pre-existing vaccine immunity to spike while also causing a strong immune response to nucleocapsid.

COH04S1 elicited neutralizing antibodies against the virus’ spike protein, which interacts with the human cellular ACE2 receptor, allowing the virus to enter cells of the lung, heart and other organs, resulting in damage and significant inflammation. These neutralizing antibodies were effective against the original SARS-CoV-2 and subsequent viral variants. T cells were produced against the SARS-CoV-2 nucleocapsid protein, as well as its spike protein, after just one dose of COH04S1. 

“This data confirms the powerful dual action of our vaccine,” said Don J. Diamond, Ph.D., professor in City of Hope’s Department of Hematology & Hematopoietic Transplantation and the vaccine’s lead developer. "Given the multiple mutations in spike, leading to variants of concern and inconsistent protection from existing FDA-approved vaccines, we are excited about our approach incorporating two antigens in one vaccine. Should a new mutation arise in the spike antigen that interferes with antibody recognition, we believe a person vaccinated with our vaccine would still have substantial T cell immunity against both the nucleocapsid and spike antigens that would protect them from the ravages of COVID-19.

“The T cell response is especially important for immunocompromised cancer patients as they can readily lose the ability to produce antibodies during and after chemotherapy or other treatments that deplete antibody-producing cells,” he added.

In November 2021, GeoVax licensed the vaccine for further development and commercialization, including potentially as a first-line COVID-19 vaccine. GeoVax has now designated the vaccine as GEO-CM04S1.

“Our license of GEO-CM04S1 (formerly known as COH04S1) represented a significant and exciting milestone for GeoVax, and the data published today confirm the validity of the vaccine’s approach against SARS-CoV-2,” said David Dodd, GeoVax president and CEO. “We believe the vaccine, containing the two antigens, S and N, along with the recognized antibody and cellular immune responses resulting from the MVA approach, has the potential to offer a more robust and durable booster protection than that from the current vaccines in use, as well as provide a greater degree of protection within immunocompromised patients.”

“We have developed a strong working relationship with Dr. Diamond and his colleagues at City of Hope as we make plans to accelerate the clinical advancement of this promising vaccine for patients and look for opportunities for further collaboration in other areas of vaccine and immunotherapy needs,” Dodd added.

For the Phase 1 trial at City of Hope, 58 healthy adult volunteers participated and 34 participants received two doses of COH04S1 28 days apart. Five received two placebo doses and 13 volunteers received a first dose of the vaccine and a second dose of the placebo. Volunteers who received the placebo were informed 56 days after first injection — of either the vaccine or placebo — that they didn’t receive one or both vaccine injections. They were offered COH04S1 or one of the then-emergency use authorized vaccines as a second dose.

T cells against the spike and nucleocapsid proteins were induced following the first dose of COH04S1. Following the second dose, given four weeks after the first, high amounts of neutralizing antibodies were detected at the next monitoring period.

All vaccinated volunteers reached the primary immunological endpoint, defined as a four-fold increase of antibodies against the spike or nucleocapsid protein eight weeks after the first dose.

“Our vaccine could potentially be used as a first vaccination, or a booster to previous vaccinations, as it would boost antibodies to the spike protein and help generate T cells,” Diamond added.

The Phase 2 clinical trial of COH04S1 is the first to study the safety and effectiveness of an investigational vaccine in patients with blood cancer who have received a bone marrow transplant or chimeric antigen receptor (CAR) T therapy. The trial is also the first to compare an investigational COVID-19 vaccine to the Pfizer Cominarty vaccine in people who are immunocompromised and receiving immunosuppressive therapy.

The Phase 2 booster study is for healthy individuals, 18 years of age and older, who were previously vaccinated with one of the FDA-approved mRNA vaccines or the FDA-authorized Johnson & Johnson vaccine. The study is designed as a dose-escalation trial to evaluate the safety profile and immune response of COH04S1 as a booster shot. The immunological responses measured will include both the level of neutralizing antibodies against SARS-CoV-2, including omicron and T cell responses.

To produce the vaccine, a team led by Felix Wussow, Ph.D., and Flavia Chiuppesi, Ph.D., both City of Hope assistant research professors in the Department of Hematology & Hematopoietic Cell Transplantation, together with Diamond, first developed a synthetic modified vaccinia ankara (MVA) virus platform technology to house the genetic components that make up the vaccine at a molecular level. The natural form of the MVA virus, currently used in a smallpox vaccine, is approved by the FDA and has a record of safety and efficacy, rapid immune response and lasting protection in both healthy and immunocompromised patients. City of Hope has experience using the natural virus for transplant-related vaccines, such as the Triplex vaccine, which was used in a Phase 2 trial to prevent cytomegalovirus in immunocompromised stem cell transplant recipients and an oncologic-based vaccine as a therapeutic in breast, head and neck, ovarian, and other cancers.

About City of Hope

City of Hope's mission is to deliver the cures of tomorrow to the people who need them today. Founded in 1913, City of Hope has grown into one of the largest cancer research and treatment organizations in the U.S. and one of the leading research centers for diabetes and other life-threatening illnesses. As an independent, National Cancer Institute-designated comprehensive cancer center, City of Hope brings a uniquely integrated model to patients, spanning cancer care, research and development, academics and training, and innovation initiatives. Research and technology developed at City of Hope has been the basis for numerous breakthrough cancer medicines, as well as human synthetic insulin and monoclonal antibodies. A leader in bone marrow transplantation and immunotherapy, such as CAR T cell therapy, City of Hope’s personalized treatment protocols help advance cancer care throughout the world.

With a goal of expanding access to the latest discoveries and leading-edge care to more patients, families and communities, City of Hope’s growing national system includes its main Los Angeles campus, a network of clinical care locations across Southern California, a new cancer center in Orange County, California, scheduled to open in 2022, and Cancer Treatment Centers of America. City of Hope’s affiliated family of organizations includes Translational Genomics Research Institute and AccessHope^TM. For more information about City of Hope, follow us on Facebook, Twitter, YouTube, Instagram and LinkedIn.

About GeoVax

GeoVax Labs Inc. is a clinical-stage biotechnology company developing human vaccines and immunotherapies against infectious diseases and cancer using novel proprietary platforms. GeoVax’s product pipeline includes two ongoing Phase 2 clinical trials of GEO-CM04S1 (formerly COH04S1) for COVID-19 as a universal booster vaccine to mRNA vaccines authorized by the U.S. Food and Drug Administration (FDA) and as a primary vaccine for use in immunocompromised patients. In addition to GEO-CM04S1 for COVID-19, GeoVax is developing GEO-CM02 as a pan-coronavirus vaccine. The company is also conducting a Phase 1/2 clinical trial of Gedeptin^® for treatment of head and neck cancer. Gedeptin^® has been granted orphan drug status by the FDA. Additional research and development programs include preventive vaccines against Zika virus, hemorrhagic fever viruses (Ebola, Sudan, Marburg and Lassa) and malaria, as well as immunotherapies for multiple solid tumors. The company’s portfolio of wholly owned, co-owned, and in-licensed intellectual property stands at over 70 granted or pending patent applications spread over 20 patent families.

For additional information about GeoVax, visit our website 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 registration statement on Form S-1 and the 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 U.S. federal securities law.