Exhibit 99.1
Vaccinex Reports Positive Effect of Pepinemab Treatment on New Biomarker of Brain Inflammation
in Neurodegenerative Diseases
Pepinemab, anti-SEMA4D blocking antibody, appears to inhibit astrocyte activation and brain inflammation as evidenced by significantly
reduced levels of GFAP in patient blood.
ROCHESTER, N.Y., October 26, 2023 — Vaccinex, Inc. (Nasdaq: VCNX), a
clinical-stage biotechnology company, today reports novel findings for its lead product, pepinemab, in a highlighted podium presentation at the Clinical Trials on Alzheimer’s Disease (CTAD) Conference in Boston, MA. Vaccinex has previously
reported results of a phase 2 trial in Huntington’s disease (HD) that suggest pepinemab treatment prevents decline in glucose uptake associated with astrocyte activation and significantly slows cognitive decline as measured by the
Huntington’s Disease Cognitive Assessment Battery (HD-CAB). The company now reports data indicating that pepinemab treatment significantly reduced blood levels of GFAP, a biomarker of reactive astrocytes,
providing further evidence of the drug’s potential to reverse harmful astrocyte activation and brain inflammation.
Astrocytes are key regulatory
cells in the brain that, under conditions of brain injury or disease, switch from their normal supportive physiological functions to inflammatory activity that is believed to aggravate damage to brain tissue. This transition is marked by release of
glial fibrillary acidic protein (GFAP), a characteristic astrocyte protein, into blood. Importantly, results from a highly sensitive S-PLEX GFAP immunoassay demonstrated a significant reduction in plasma GFAP
levels in HD patients treated with pepinemab compared to those receiving placebo. Elevated GFAP levels in blood have also been found to correlate with Aß amyloid deposits in brain and to be associated with higher risk of dementia and faster
rates of cognitive decline in AD. A committee convened by the Alzheimer’s Association has recently recommended GFAP as a leading blood-based biomarker of astrocytic activation and brain inflammation in AD.
Given the many physiological parallels between neurodegenerative processes in HD and AD, we believe that similar biological effects of pepinemab treatment are
likely in the two indications. This is being tested in an ongoing randomized, placebo-controlled trial, SIGNAL-AD, supported by awards from the Alzheimer’s Drug Discovery Foundation and the
Alzheimer’s Association, for which it is anticipated that the last patient will complete 12 months of treatment by June 2024. Early evidence of limited benefit to AD patients treated with antibodies to Aß amyloid has stimulated a search
for differentiated treatments that could further improve responses. It has been known for some time that beta amyloid deposits can also be present in the brain of elderly subjects who do not progress to Alzheimer’s. As noted by Howard Fillit,
MD, Chief Science Officer for the Alzheimer’s Drug Discovery Foundation, “If there’s no strong immune reaction to the buildup, there’s no inflammation and no progression of disease.” We believe that preventing astrocyte
activation and reducing brain inflammation with pepinemab treatment could be an attractive alternative or complement to anti-Aß antibodies with potential for greater efficacy.
About Pepinemab
Pepinemab is a humanized IgG4 monoclonal
antibody designed to block SEMA4D, which can trigger collapse of the actin cytoskeleton and loss of homeostatic functions of astrocytes and glial cells in the brain and dendritic cells in immune tissue. Pepinemab has been administered to more than
400 patients and appears to be well-tolerated and to have a favorable safety profile.