Pepinemab Melanoma Pilot Study Reports Tumor Immune Remodeling, With Efficacy Still Unproven
Published in Drugs development & discovery, Immunology, Journals.
Publication date: October 8, 2026. News announcement: October 7, 2026.
Vaccinex announced a Nature Communications publication from an Emory University and Winship Cancer Institute pilot trial studying the SEMA4D-blocking antibody pepinemab before surgery in resectable metastatic melanoma. Thirty-eight patients participated in the biomarker-focused study, registered as NCT03769155.
Pepinemab was evaluated with nivolumab and/or ipilimumab. Patients received two pre-surgical doses. According to the announcement, treatment neither delayed nor prevented planned surgery, and no grade 4 or 5 adverse events occurred before or after surgery.
The predefined primary biomarker endpoint was met. Pepinemab-containing regimens were associated with changes in immune-cell recruitment, antigen-presentation signals and organized lymphoid aggregates within tumors. Greater abundance of mature aggregates correlated with longer recurrence-free survival.
These exploratory associations do not establish that pepinemab improves clinical outcomes. The small trial was not powered to demonstrate efficacy, and larger randomized studies are needed. Vaccinex supplied the antibody and supported the research.
Source: Vaccinex release, October 7, 2026. Research paper: Nature Communications, DOI 10.1038/s41467-026-78231-3.