NANOBIOTIX announced updated data from two presentations at the 2023 Annual Congress of the European Society for Medical Oncology (ESMO). POSTER #1631P: Phase 1 Study of Endoscopic Ultrasound (EUS)-guided NBTXR3 delivery activated by Radiotherapy (RT) for Locally Advanced or Borderline Resectable Pancreatic Cancer (LAPC or BRPC). The 5-year overall survival rate for patients with unresectable locally advanced pancreatic cancer (LAPC) remains less than 5%. Normally, these patients receive the combination of cytotoxic chemotherapy followed by concurrent chemoradiation if no metastatic progression has occurred. Innovative new treatments that might extend survival and avoid additional harmful side effects are an urgent unmet need for this patient population. With safety, feasibility, and the recommended Phase 2 dose (RP2D) previously determined and reported, this presentation from The University of Texas MD Anderson Cancer Center (MD Anderson) explored additional preliminary signals of efficacy from the ongoing Phase 1 study evaluating RT-activated NBTXR3 after cytotoxic chemotherapy for patients with LAPC to potentially inform next steps in clinical trial development. An MD Anderson historical review of 243 patients treated with LAPC at the same center showed: Normalization of the biomarker CA19-9, a surrogate indicator for longer survival, in approximately 17% of patients treated with the standard of care who had elevated CA19-9 levels at diagnosis (n=183), Median Overall Survival (mOS) of 19.2 months in 144 patients who received cytotoxic chemotherapy followed by RT with or without concurrent or maintenance chemotherapy (80% received RT with concurrent chemotherapy). Comparatively, preliminary data from 17 patients treated with cytotoxic chemotherapy followed by RT-activated NBTXR3 in the Phase 1 LAPC study show:
Normalization of CA19-9 in 42% of patients who had elevated levels at diagnosis (n=12). An mOS of 23 months from diagnosis. The investigator concluded that these results suggest promising anti-tumor efficacy for NBTXR3 in LAPC. The previously reported final efficacy analysis of Study 102?a Phase 1 dose escalation and dose expansion study evaluating RT-activated NBTXR3 for elderly, frail patients with locally advanced head and neck cancer found that therapy was feasible, well tolerated with a favorable safety profile, and showed both prolonged Progression-Free Survival (PFS) and OS in a population characterized by negative prognostic factors. This new exploratory analysis showed an mOS of 42.8 months in the 36 evaluable patients who had complete or partial response to NBTXR3 in the injected lesion (81.8%), compared to an mOS of 18.1 months observed in All Patients Treated (n=56), and 23.1 months in the total evaluable population (n=44), respectively. In addition, a positive correlation between Objective Response to RT-activated NBTXR3 in the injected lesion, Local Progression-Free Survival, and the extension of Overall Survival was observed. These data suggest that the high rate of Objective Response to RT-activated NBTXR3 could potentially extend PFS and OS for elderly, frail patients with locally advanced head and neck cancer.