Atlanta, GA — December 8, 2025 — Leads & Copy — GeoVax Labs, Inc. (Nasdaq: GOVX) has announced the publication of a peer-reviewed article in JCO Oncology Advances, the American Society of Clinical Oncology’s (ASCO) open-access journal, regarding its Phase 1/2 clinical trial of Gedeptin® for recurrent head and neck cancer.
The manuscript, titled “A Phase 1/2 Study of Intratumoral Ad/PNP (Gedeptin) with Fludarabine Phosphate in Subjects with Recurrent Head and Neck Cancer”, details findings from a multi-center clinical trial evaluating repeated cycles of Gedeptin®, a gene-directed enzyme prodrug therapy (GDEPT), administered via intratumoral injection followed by systemic fludarabine.
The Phase 1/2 trial enrolled patients with recurrent head and neck cancers who had exhausted all standard treatment options and had undergone a median of four prior lines of systemic therapy. Patients received therapy on a 28 day schedule, each consisting of intratumoral Gedeptin injections followed by intravenous fludarabine.
Key results from the publication include:
The study indicated an acceptable safety profile with no new safety signals. Serious adverse events were uncommon and generally unrelated to treatment, and no deaths were attributed to study therapy.
Clinical evidence suggested disease stability, with three of eight patients (37.5%) achieving stable disease.
Tumor biopsies confirmed uptake and expression of the therapeutic E. coli PNP transgene in all evaluable patients, supporting the mechanistic foundation of the Gedeptin platform.
Study results suggest that earlier intervention, higher vector dosing, improved tumor transduction, or combination therapy may further increase efficacy. Preclinical findings cited in the manuscript show that Gedeptin-mediated tumor destruction may sensitize tumors to checkpoint inhibitors, offering a promising path forward.
J. Marc Pipas, MD, Executive Medical Director, Oncology of GeoVax, stated that the publication reinforces the strong scientific rationale underpinning the Gedeptin platform. He noted that even in a highly refractory patient population, repeated intratumoral dosing of Gedeptin demonstrated a favorable safety profile and evidence of disease stability. Correlative analyses confirmed robust tumor transduction and PNP expression, a critical mechanistic milestone for gene-directed enzyme prodrug therapy.
Kelly T. McKee, MD, MPH, Chief Medical Officer of GeoVax, added that the results support the continued development of Gedeptin in settings where tumor burden is lower, patients are less heavily pretreated, or where combination strategies, particularly with immune checkpoint inhibitors, may amplify therapeutic benefit. She mentioned this aligns with their strategy to advance Gedeptin into neoadjuvant studies for surgically resectable recurrent head and neck cancers.
David Dodd, Chairman & CEO of GeoVax, stated that the publication in the ASCO journal underscores both the scientific significance of this trial and the need for new approaches to treat recurrent head and neck cancers. He said Gedeptin’s targeted mechanism, combined with its repeat-dosing feasibility, offers a promising therapeutic option for patients, and they look forward to expanding development into earlier disease settings and into rational combination regimens.
Gedeptin is a non-replicating adenoviral vector delivering theE. coli purine nucleoside phosphorylase (PNP) gene directly into tumor tissue. Following intratumoral injection, patients receive systemic fludarabine, which is converted in PNP-expressing tumor cells into a potent cytotoxic metabolite.
Key characteristics of Gedeptin include:
A tumor-agnostic mechanism of action, driven by localized intratumoral activation of fludarabine into the potent cytotoxin F-Ade, enabling activity independent of tumor histology or proliferation rate.
A strong bystander effect, in which the activated F-Ade diffuses to neighboring cancer cells – allowing Gedeptin to kill tumor cells even when only a small fraction is directly transduced.
Immune-sensitizing properties that enhance tumor antigen visibility and may improve responses to immune checkpoint inhibitors.
A favorable safety profile, demonstrated across early Phase 1 and Phase 1/2 studies and supported by consistent tolerability in heavily pretreated solid tumor patients.
Gedeptin is now progressing toward combination-therapy in a neoadjuvant clinical program, with plans to evaluate Gedeptin with agents such as pembrolizumab aiming to strengthen antitumor immune activation.
Company Contact:
info@geovax.com
678-384-7220
Media Contact:
Jessica Starman
media@geovax.com
Source: GeoVax Labs, Inc.
