• All 24 patients completed treatment with no dose-limiting toxicities, no Grade 3 or higher adverse events related to JNJ-1900 (NBTXR3 or to the injection procedure, and intratumoral injection was deemed feasible
• One-year locoregional control rate was 79%, one-year local progression-free survival (LPFS) was 61%, and one-year overall survival (OS) was 70% in evaluable subjects— achieved at a lower re-irradiation dose than patients’ prior course of radiotherapy
• Investigators concluded that JNJ-1900 (NBTXR3 may permit clinically meaningful local control using a substantially lower re-irradiation dose than patients’ prior course of radiotherapy
• Enrollment in the dose-escalation and expansion parts of the study is complete per protocol; following the encourage findings, additional patient enrollment in this study is planned

Data presented at the IASLC 2026 World Conference on Lung Cancer

NANOBIOTIX (Euronext: NANO - NASDAQ: NBTX - the “Company”), a late-stage clinical biotechnology company pioneering physics-based approaches to expand treatment possibilities for patients with cancer and other major diseases, today announced updated safety and efficacy data from the completed dose-escalation and expansion phases of a Phase 1 study sponsored by The University of Texas MD Anderson Cancer Center (“UT MD Anderson”) evaluating radiotherapy-activated JNJ-1900 (NBTXR3) for patients with inoperable, locoregionally recurrent non-small cell lung cancer (“NSCLC”) amenable to re-irradiation (“reRT”). The data were presented by study principal investigator Saumil Gandhi, MD, PhD, at the International Association for the Study of Lung Cancer (“IASLC”) 2026 World Conference on Lung Cancer (“WCLC”), taking place September 12–15, 2026 in Seoul, Republic of Korea.

POSTER P2.260: Re-irradiation (ReRT) with NBTXR3 for Inoperable Locoregionally Recurrent Non-Small Cell Lung Cancer (NSCLC): A Phase I Trial

Saumil N. Gandhi, MD, PhD; Enoch Chang, MD; Aileen B. Chen, MD; Stephen G. Chun, MD; Joe Y. Chang, MD, PhD; Steven H. Lin, MD, PhD; Matthew S. Ning, MD, MPH; David Qian, MD; Julianna K. Bronk, MD, PhD; Rahul A. Sheth, MD; Jianjun Zhang, MD, PhD; Tina Cascone, MD, PhD; Marcelo Vailati Negrao, MD; Anne S. Tsao, MD; George R. Blumenschein, MD; Mehmet Altan, MD; John V. Heymach, MD, PhD; James W. Welsh, MD; Suyu Liu, PhD; Zhongxing Liao, MD; Roberto F. Casal, MD — The University of Texas MD Anderson Cancer Center

Patients who are candidates for re-irradiation are frequently limited to palliative radiation doses because of normal-tissue tolerance, and their recurrent tumors typically harbor the most radiation-resistant cells. Effective strategies to safely deliver radiotherapy doses capable of controlling recurrent tumors remain a significant unmet need in this setting.

“Recurrence within a previously irradiated field is one of the least forgiving problems in thoracic oncology,” said Saumil Gandhi, MD, PhD, Department of Thoracic Radiation Oncology, Division of Radiation Oncology at UT MD Anderson. “The normal tissue near the tumor has already received a full course of radiation, so the dose that can delivered safely during a second course is limited. Additionally, the disease that returns is often more radioresistant because it survived radiation the first time. In this study, JNJ-1900 (NBTXR3) was delivered without dose-limiting toxicities, and we observed clinically meaningful local control at a substantially lower re-irradiation dose. These findings warrant evaluation in a randomized trial.”

Results from the pooled dose-escalation and expansion phases showed that all 24 patients completed treatment with JNJ-1900 (NBTXR3) plus re-irradiation with no dose-limiting toxicities. Investigators reported no Grade 3 or higher adverse events related to JNJ-1900 (NBTXR3) or to the injection procedure.

Grade 3 radiotherapy-related adverse events occurred in 33% of patients (n=8), and Grade 5 radiotherapy-related adverse events in 8% (n=2). The recommended Phase 2 dose was established at 33% of gross tumor volume.

At a median follow-up of 12 months (data cutoff: August 2026) the one-year locoregional control rate was 79%. One-year local progression-free survival (“LPFS”) was 61% (median 13.6 months), and one-year overall survival (“OS”) was 70% (median 14.8 months). Investigators concluded that JNJ-1900 (NBTXR3) may permit clinically meaningful local control using a substantially lower re-irradiation dose.

“The Nanobiotix team is encouraged by these full-cohort findings in one of the most difficult settings in lung cancer,” said Louis Kayitalire, MD, Chief Medical Officer of Nanobiotix. “If a physics-based approach can improve local control in tissue that has already failed radiation, and do so at a reduced dose, then the conditions in earlier settings, where full-dose radiotherapy reaches previously untreated tissue, could be even more favorable. We look forward to further evaluation in additional patients enrolled to this study and across indications.”

Enrollment in both the dose-escalation and expansion parts of the study is complete per protocol. Following the encouraging findings, additional patient enrollment in this study is planned.