Tokyo, Japan — December 10, 2025, 10:00 AM JST — NEC Bio Therapeutics today presents results from the Phase I basket clinical trial of an orally administered cancer vaccine, NECVAX-NEO1, used in combination with checkpoint inhibitors (CPIs) for treating patients with solid tumors. The findings are being presented in a poster at the ESMO Immuno-Oncology Congress in London, United Kingdom, from December 10 to 12, 2025.

NECVAX-NEO1 is a personalized bacteria-based oral DNA therapeutic vaccine, developed using AI prediction of the most immunogenic patient-specific neoepitopes. This vaccine is designed to activate a patient’s immune system, prompting a T-cell response that can precisely target and eliminate tumor cells based on an individual’s unique neoantigens.

In the phase I study, 6 patients with melanoma, renal cell cancer, or head and neck cancer, who have been on CPI treatment for at least three months, were treated with NECVAX-NEO1. The safety run-in phase showed no treatment-related toxicities, allowing a dose increase. Clinically, 83% of the patients achieved stable disease at the end of 24 weeks of treatment, which was followed by a 12 week follow-up period. In all patients immunogenic neoepitopes used in the vaccine, were detected, as demonstrated by ELISPOT analysis.

Regarding the results of the clinical study, Dr. Heinz Lubenau, CEO of NEC Bio Therapeutics, commented, "Our clinical Phase I data are demonstrating promising immune responses in treated cancer patients. The translational biomarker data are in line with the clinical data so that we are presenting a consistent data set. The progress is encouraging as we advance two additional clinical studies in 3 European countries in both early- and later-stage cancer settings. We look forward to further evaluating NECVAX-NEO1 as a potential treatment option for cancer patients with hard-to-treat tumors."

Motoo Nishihara, Corporate Executive Vice President and CTO of NEC Corporation, further commented, "We are proud to present the progress of the NECVAX-NEO1 trial, which demonstrates safety as well as signs of immunogenicity and early efficacy. NECVAX-NEO1 is the first oral cancer vaccine asset to be clinically developed by NEC. The results of this trial are a testament to our proprietary AI predictive software that supports immunological and clinical readouts. This development aligns closely with NEC’s broader mission to deliver global healthcare solutions using state-of-the-art technologies developed in-house."

Details of the poster are below:

Poster title: NECVAX-NEO1, a bacteria-based personalized neoepitope vaccine combined with PD-1/PD-L1 checkpoint inhibition in a phase I, open-label, multicenter study: safety, immunogenicity and early efficacy signals. NCT05354323

Authors: D. Vaitiekus, E. Juozaityte, L. Puzauskienė, S. Tulyte-Kirzova, L. Gatijatullin, M. Platten, I. Poschke, I.Hülsmeyer, A. Kuhn, A. Aranguren, H. Lubenau, R. Stratford, T. Clancy, H. Fontenelle, B. Simovski, Y. Yamashita, C. Chaput, A. Meiser, V. Urbonas

Poster Number: 258P

Date: 10 December 2025

The poster may also be found here: https://www.nec-bio.com/en_DD/img/20251210_ESMO2025_NECVAX-NEO1_poster.pdf
Trial details can also be viewed at: NCT05354323

NECVAX-NEO1 is currently under evaluation at additional clinical trial sites in Germany, Spain, and Lithuania.

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About NEC Bio Therapeutics
NEC Bio Therapeutics, established in Mannheim, Germany, focuses on the clinical strategy and development, as well as planning and execution of clinical trials in the oncology area. It is a subsidiary of NEC Bio, the biotech arm of NEC Corporation. NEC Bio is located in the Netherlands and dedicated to the development of innovative biotechnological solutions to tackle some of the most pressing health challenges. NEC Bio's research and development efforts are focused on creating personalized therapies that improve the quality of life for patients worldwide. NEC OncoImmunity in Oslo, Norway, is also a subsidiary of NEC Bio. For more information, visit: www.nec-bio.com.

About NEC Corporation
NEC Corporation has established itself as a leader in the integration of IT and network technologies while promoting the brand statement of “Orchestrating a brighter world.” NEC enables businesses and communities to adapt to rapid changes taking place in both society and the market as it provides for the social values of safety, security, fairness and efficiency to promote a more sustainable world where everyone has the chance to reach their full potential.
For more information, visit NEC at https://www.nec.com.