Nanobiotix Reports Phase 1 Study Results for NBTXR3 in Melanoma

Biotechnology company Nanobiotix announced new findings from an ongoing Phase 1 study evaluating its NBTXR3 therapeutic agent in combination with immune checkpoint inhibitors. The study focused on patients with primary cutaneous melanoma whose cancer had progressed despite prior anti-PD-1 therapy.

The data, presented at the 2025 ImmunoRad conference, indicated a favorable safety profile and early efficacy signals in a heavily pre-treated patient population. All 21 patients in the analysis had advanced disease that progressed on previous therapies, including anti-PD-1. The treatment regimen involved a single intratumoral injection of NBTXR3, followed by radiotherapy and then anti-PD-1 therapy.

The treatment was found to be safe and feasible at the recommended Phase 2 dose. Sixteen patients experienced treatment-related adverse events within the overall regimen, with five experiencing events related to NBTXR3 or the injection procedure itself. Only one patient reported Grade 3 or higher adverse events.

Regarding efficacy, the 19 evaluable patients showed an objective response rate (ORR) of 47.4% and a disease control rate (DCR) of 78.9%. The median overall survival (mOS) was 14.6 months. Notably, a correlation was observed between the depth of local tumor response and systemic tumor regression, suggesting a potential immune-priming effect. Nanobiotix plans to conduct further investigations, including randomized trials, to confirm the treatment's potential.