Nanobiotix: median overall survival of 17.8 months in anti-PD-1 resistant melanoma
Nanobiotix presented on October 24, 2026, at the European Society for Medical Oncology (ESMO) Congress in Madrid, the complete results of the melanoma cohort from its phase 1 trial "Study 1100". The trial combines JNJ-1900 (NBTXR3), radiotherapy and anti-PD-1 immunotherapy (pembrolizumab or nivolumab). In 24 patients whose disease progressed despite anti-PD-1 treatment, median overall survival reached 17.8 months and median progression-free survival 6.9 months.
The press release recalls that scientific literature reports, in this population, a median progression-free survival of approximately three months and a median overall survival of approximately one year. However, these data come from a single-arm study, which the principal investigator himself qualifies as preliminary. The drug candidate is being developed globally by Janssen, a Johnson & Johnson company, under the licensing agreement announced in 2023.
Response rate of 41.7%, including four complete responses
According to RECIST 1.1 criteria, the objective response rate is 41.7%, or 10 patients out of 24 evaluable, including 4 complete responses. The disease control rate reaches 75% (18 patients out of 24). These figures were presented by Dr. Jason Chan, Associate Professor of Radiation Oncology at the University of California, San Francisco.
The document distinguishes two levels of response. On lesions injected with JNJ-1900 (NBTXR3), the objective response rate is 45.8% (11 patients out of 24 evaluable). On non-injected lesions, it is 30.0%, but on only 10 evaluable patients (3 responders).
The responses observed at distance from the treated lesion are at the heart of the mechanism claimed by the company: the product, composed of hafnium oxide nanoparticles activated by radiotherapy, is designed to destroy tumor cells in the injected tumor and then trigger an adaptive immune response.
Heavily pretreated population and acceptable safety profile
All 24 patients included had advanced melanoma resistant to anti-PD-1, of which 14 were stage IV. Before inclusion, 50% had received anti-CTLA-4, 33.3% anti-LAG-3 and 25% T-VEC. For 87.5% of them, the most recent treatment was immunotherapy.
The protocol is based on a single intratumoral injection, at the recommended dose for phase 2 (33% of the total tumor volume), followed by stereotactic radiotherapy targeting the injected lesion, then anti-PD-1. The investigators report an acceptable safety profile and demonstrated feasibility across a wide range of lesions, regardless of their size and location. No new safety signals were identified.
Dr. Louis Kayitalire, Medical Director of Nanobiotix, indicates that this analysis, covering more patients and longer follow-up, demonstrates a consistent safety profile and an improvement in overall survival compared to the initial published data.
Single-arm data that investigators want to test in a randomized trial
Several elements of the document circumscribe the scope of these results. The study is a phase 1 dose expansion trial, single-arm: comparisons with the literature therefore do not rely on a control group. The sample size is 24 patients, and the analysis on non-injected lesions covers only 10 of them.
The immunological component is explicitly exploratory. In a subgroup of 8 patients, IL-1β is the plasma cytokine that increased the most after treatment, among those analyzed. Dr. Jason Chan believes that this increase suggests immune activation that justifies further investigation.
The investigators conclude that these data justify evaluation in randomized trials, in patients with cutaneous melanoma naïve or resistant to anti-PD-1. In other indications, Johnson & Johnson is notably conducting NANORAY-312, a global phase 3 randomized trial in locally advanced head and neck squamous cell carcinoma.
From a stock market perspective, the publication comes after a 34% increase in the share price over one week, noted on October 23, 2026, which followed a 25.5% decline over one month observed on October 21. On the substance, the most structuring element remains the median overall survival of 17.8 months achieved in these 24 patients who failed anti-PD-1.
