ROCHESTER, N.Y., July 08, 2026 (GLOBE NEWSWIRE) -- Vaccinex, Inc., a clinical-stage biotechnology company pioneering a differentiated approach to treating Alzheimer’s disease (AD) through the inhibition of Semaphorin 4D (SEMA4D), today announced that it will present promising new biomarker data from its Phase 1b/2 trial to support plans for an enlarged randomized phase 2B SIGNAL-AD study of pepinemab for treatment for early Alzheimer’s disease at the Alzheimer’s Association International Conference in London, United Kingdom, on July 13, 2026. Elizabeth Evans, PhD, Chief Operating Officer and Senior VP Discovery and Translational Medicine, will chair the Featured Research Session and present novel results of the SIGNAL-AD phase 1/2 study and plans for continued investigation in the SIGNAL-AD2 study.

Presentation title: Glial Biomarkers Associated With Disease Progression Are Regulated By SEMA4D Blocking Antibody Pepinemab in Patients with Early-stage AD

Session Chair and Presenter: Elizabeth Evans, PhD

Session Date: Monday, 7/13/2026 9:00:00 AM - 10:30:00 AM (London time)

Venue: Excel London

Pepinemab’s novel mechanism of action, a differentiated approach to treating neurodegenerative disease:

Vaccinex scientists discovered that Semaphorin 4D (SEMA4D), a molecule that binds to plexin-B1 receptors expressed on astrocytes in the brain, is highly upregulated on stressed or damaged neurons during progression of Alzheimer’s Disease (AD)
The Company’s hypothesis, which is being tested in the Phase 1b/2 SIGNAL-AD study, is that treating with pepinemab antibody can block SEMA4D signaling through astrocyte plexin-B1 receptors and slow or prevent the damaging consequences of astrocyte activation.
An independent transcriptomic meta-analysis by a team of researchers led by Dr. Philip De Jager at Columbia University Medical Center, identified a unique reactive astrocyte subset that was strongly associated with cognitive impairment and Alzheimer’s Disease progression.
Through a collaboration, scientists from Vaccinex and Dr. De Jager’s team discovered key biomarkers of reactive astrocytes and dynamic disease processes associated with synaptic loss, cognitive decline and neuroinflammation that appear to be regulated by pepinemab treatment.
Evidence from these studies support and inform the design of an enlarged randomized Phase 2B trial "SIGNAL-AD2" for the treatment of people living with early Alzheimer's dementia.

The SIGNAL-AD study was funded in part by a grant from the Alzheimer’s Association as well as by investments from the Alzheimer’s Drug Discovery Foundation (ADDF).

About Pepinemab

Pepinemab is a humanized IgG4 monoclonal antibody designed to block SEMA4D, which can otherwise bind to plexin-B1 receptors to trigger collapse of the actin cytoskeleton in cells and lead to loss of homeostatic functions of astrocytes and other glial cells in the brain and of dendritic cells in immune tissue. Pepinemab appears to be well-tolerated with a favorable safety profile in multiple clinical trials in different neurological and cancer indications.

About Vaccinex Inc.

Vaccinex, Inc. is pioneering a differentiated approach to treating slowly progressive neurodegenerative diseases and cancer through the inhibition of semaphorin 4D (SEMA4D). The Company’s lead drug candidate, pepinemab, blocks SEMA4D, a potent biological effector that it believes triggers damaging inflammation in chronic diseases of the brain and prevents infiltration and activation of immune cells in tumors. Pepinemab is being studied as a monotherapy in the Phase 1b/2 SIGNAL-AD study in Alzheimer’s Disease, and the Company has previously published promising Phase 2 data in Huntington’s disease. In oncology, pepinemab is being evaluated in combination with KEYTRUDA® in the Phase 1b/2 KEYNOTE-B84 study in recurrent or metastatic head and neck cancer (HNSCC) and in combination with BAVENCIO® in a Phase 1b/2 study in patients with metastatic pancreatic adenocarcinoma (PDAC). The oncology clinical program also includes several investigator-sponsored studies in solid tumors including breast cancer and melanoma.

Vaccinex has global commercial and development rights to pepinemab and is the sponsor of the KEYNOTE-B84 study which is being performed in collaboration with Merck Sharp & Dohme Corp, a subsidiary of Merck and Co, Inc. Kenilworth, NJ, USA. Additional information about the study is available at: clinicaltrials.gov.

KEYTRUDA is a registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co. Inc., Kenilworth, NJ, USA. BAVENCIO®/avelumab is provided by Merck KGaA, Darmstadt, Germany, previously as part of an alliance between the healthcare business of Merck KGaA, Darmstadt, Germany and Pfizer.

Forward Looking Statements

To the extent that statements contained in this press release are not descriptions of historical facts regarding Vaccinex, Inc. ("Vaccinex," "we," "us," or "our"), they are forward-looking statements reflecting management’s current beliefs and expectations. Such statements include, but are not limited to, statements about expectations and objectives with respect to the results and timing of the SIGNAL-AD clinical trials; our plans, expectations and objectives with respect to the results and timing of the SIGNAL-AD and KEYNOTE-B84 clinical trials; the use and potential benefits of pepinemab in R/M HNSCC, lung cancer, metastatic pancreatic adenocarcinoma (PDAC) and other indications; the potential for benefits as compared to single agent KEYTRUDA® or BAVENCIO®; expectations with respect to the collaboration of Merck,; and other statements identified by words such as "anticipate," "believe," "plans," "schedule," "being," "will," "appears," "expect," "ongoing," "potential," "promising," "suggest", and similar expressions or their negatives (as well as other words and expressions referencing future events, conditions, or circumstances). Forward-looking statements involve substantial risks and uncertainties that could cause the outcome of our research and pre-clinical development programs, clinical development programs, future results, performance, or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, uncertainties inherent in the execution, cost and completion of preclinical studies and clinical trials, that interim and preliminary data may not be predictive of final results and does not ensure success in later clinical trials, uncertainties related to regulatory approval, risks related to our dependence on our lead product candidate pepinemab, and other matters that could affect our development plans or the commercial potential of our product candidates. Except as required by law, the Company assumes no obligation to update these forward-looking statements. For a further discussion of these and other factors that could cause future results to differ materially from any forward-looking statement, see the section titled "Risk Factors" in our periodic reports and the other risks and uncertainties described in the Company’s annual year-end filings.

Investor Contact

Elizabeth Evans, PhD

Chief Operating Officer, Vaccinex, Inc.

(585) 271-2700

eevans@vaccinex.com