NEC Bio reports 5 of 8 TNBC patients with complete response on oral neoantigen therapy
NEC Bio says five of eight patients with triple-negative breast cancer reached pathological complete response when its oral, AI-designed neoantigen therapy NECVAX-NEO1 was added to chemotherapy and pembrolizumab. The company is presenting the Phase I/II data at the ESMO Congress in Madrid and is extending the trial to 28 patients, including sites in the U.S.
- NEC Bio presents Phase I/II data for oral neoantigen therapy NECVAX-NEO1 at ESMO 2026 in Madrid.
- In the first cohort of 8 TNBC patients, 5 achieved pathological complete response at surgery.
- Immunogenic neoepitopes were detected in all patients by ELISPOT, and the combination was generally well tolerated.
- The trial is being extended to n=28 patients, including U.S. patients after IND approval, with a higher dose in cohort 2.
What the first cohort showed
NEC Bio, the biotechnology arm of NEC Corporation, is presenting results from the first cohort of its Phase I/II trial in triple-negative breast cancer (TNBC). The findings are shown as an e-poster at the ESMO Congress in Madrid, Spain, which runs from October 23 to 27, 2026. The poster number is 4694eP and the trial is registered as NCT06631092.
Eight patients with TNBC were treated in a neoadjuvant setting, meaning before surgery. According to NEC, all of them received 2 courses of neoadjuvant chemotherapy and pembrolizumab before the planned surgery. After 12 weeks of chemotherapy and pembrolizumab, NECVAX-NEO1 was added on top, with an optional adjuvant treatment phase after surgery.
NEC reports that the combination was generally well tolerated. Five patients achieved pathological complete response at surgery, accompanied by corresponding biomarker changes. In all patients, the immunogenic neoepitopes used in NECVAX-NEO1 were detected, as shown by ELISPOT analysis. The company describes the data as confirming potential safety and immunogenicity and providing clinical proof-of-concept in high-risk early-stage cancer, including the perioperative setting.
How NECVAX-NEO1 works
NECVAX-NEO1 is described as an AI-powered, individualized, bacteria-based oral DNA therapy. It combines two proprietary platforms. IMMUNASIGHT® is an AI-based neoantigen prediction platform that identifies the most immunogenic patient-specific neoepitopes. TORAPRIME® is an oral delivery platform that uses attenuated bacteria to carry DNA encoding selected neoantigens through the gut immune system.
The aim, according to NEC, is to activate the patient's immune system and trigger a T-cell response that targets and eliminates tumor cells based on the individual's unique neoantigens. NEC says IMMUNASIGHT® models the complete antigen presentation pathway, from mutation identification and processing to presentation, together with immunogenicity, to narrow thousands of potential targets down to those most likely to elicit meaningful anti-tumor immune responses.
Trial expansion and next steps
Dr. Heinz Lubenau, CEO of NEC Bio Therapeutics, said the clinical data demonstrate "promising immune responses in the neoadjuvant treatment of early-stage TNBC patients." The company is extending the trial to n=28 patients, including patients in the U.S., after it recently received IND approval to run a clinical trial in the country.
Patients in cohort 2 are receiving a higher dose of NECVAX-NEO1 on top of the Keynote-522 standard of care regimen, which includes pembrolizumab. NECVAX-NEO1 is also being evaluated at additional clinical trial sites in several European countries.
Akira Kitamura, CEO of NEC Bio, said the results strengthen the company's confidence in NECVAX-NEO1 as an individualized neoantigen therapy.
What it means
The data come from a small first cohort of eight patients, and the therapy remains investigational. The results are early signals on safety, immune response and tumor response rather than a final efficacy verdict. The larger cohort with a higher dose, and the addition of U.S. sites, will show whether the pattern holds in more patients. For people with early-stage TNBC, NECVAX-NEO1 is for now a candidate under clinical evaluation, not an available treatment.
