Phase I/II NECVAX-NEO1 trial in patients with triple-negative breast cancer confirm its potential safety and immunogenicity and provide clinical proof-of-concept for the use of this investigational oral bacteria-based DNA neoantigen therapy in high-risk early-stage cancer patients including the perioperative setting as well.
Tokyo, Japan — NEC Bio will be presenting results from the Phase I/II TNBC clinical trial of its orally administered individualized neoantigen therapy, NECVAX-NEO1, used in combination with checkpoint inhibitors (CPIs) and chemotherapy for patients with triple-negative breast cancer (TNBC). The findings are being presented in an e-poster at the ESMO Congress in Madrid, Spain, from October 23 to 27, 2026.
NECVAX-NEO1 is an AI powered individualized bacteria-based oral DNA therapy that combines IMMUNASIGHT®, NEC Bio’s proprietary AI based neoantigen prediction platform for identifying the most immunogenic patient-specific neoepitopes, with TORAPRIME®, its proprietary oral bacterial neoantigen delivery platform. This therapy 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 first cohort of the phase I/II study, 8 patients with TNBC were treated with NECVAX-NEO1 in a neoadjuvant setting. All patients were treated with 2 courses of neoadjuvant chemotherapy and pembrolizumab before the planned surgery. After 12 weeks of chemotherapy/pembrolizumab, NECVAX-NEO1 was added on top, with an optional adjuvant treatment phase after surgery. NECVAX-NEO1 on top of chemotherapy/immunotherapy was generally well tolerated. Five patients achieved pathological complete response at surgery, accompanied by corresponding biomarker changes. In all patients, immunogenic neoepitopes used in NECVAX-NEO1 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/II data are demonstrating promising immune responses in the neoadjuvant treatment of early-stage TNBC patients. The results are encouraging, so we are extending the trial to n=28 patients, including patients in the U.S., as we recently received IND approval to conduct a clinical trial in the country. The additional patients in cohort 2 are being treated with a higher dose of NECVAX-NEO1 on top of Keynote-522 standard of care regimen, which includes pembrolizumab. We look forward to further evaluation of NECVAX-NEO1 as a potential treatment option for cancer patients with high medical need.”
Akira Kitamura, CEO, NEC Bio, further commented, “The results presented at ESMO 2026 are an important accomplishment that further strengthens NEC Bio’s confidence in the potential of NECVAX-NEO1 as an individualized neoantigen therapy. By combining our proprietary AI-powered neoantigen discovery platform, IMMUNASIGHT® with a differentiated neoantigen delivery platform TORAPRIME®, we aim to deliver highly individualized treatment approaches for patients with cancer. These findings support our continued commitment to advancing innovative therapies that have the potential to improve patient outcomes and expand the possibilities of precision treatment in oncology.”
Details of the poster are below:
Poster title: Phase I/II study of neoadjuvant personalized vaccination with NECVAX-NEO1, in combination with pembrolizumab and chemotherapy in early-stage triple-negative breast cancer, evaluating safety, immunogenicity, and preliminary clinical activity NCT06631092
Authors: Peter A. Fasching, Katharina Keller, Oliver Schleicher, Carlo Fremd, Laura Michel, Michael Platten, Isabel Poschke, Ingrid Hülsmeyer, Margarida Garcia, Alvaro Aranguren, Kaidre Bendjama, Daiki Mori, Heinz Lubenau, Andreas Schneeweiss
Poster Number: 4694eP
Date: 23 October 2026
The poster may also be found here:
NCT06631092
NECVAX-NEO1 is currently under evaluation at additional clinical trial sites in several European countries.
