Nanobiotix S.A. announced that the first patient has been enrolled in NANORAY-312, a global, open-label, two-arm, randomized, Investigator's Choice phase III registration study that is designed to investigate the efficacy and safety of radiotherapy-activated NBTXR3 with or without cetuximab versus radiotherapy with or without cetuximab in high-risk, chemotherapy-ineligible elderly patients with locally-advanced head and neck squamous cell carcinoma (LA-HNSCC). The study is co-led by principal investigators Sue Yom, MD, PhD, Professor and Vice Chair, Strategic Advisory Department of Radiation Oncology; Professor, Otolaryngology-Head and Neck Surgery at The University of California, San Francisco, and Christophe Le Tourneau, MD, PhD, senior medical oncologist and head of the Department of Drug Development and Innovation (D3i) at Institut Curie (Paris). Eligible participants for NANORAY-312 will be treated with NBTXR3 at a 1:1 ratio after an Investigator's Choice of radiotherapy alone or radiotherapy in combination with cetuximab.

NANORAY-312 aims to enroll 500 patients across sites in the United States, Europe, and Asia. To date, 128 sites have been qualified in 29 countries. The primary endpoint of the pivotal study is Progression-free Survival (PFS) and key secondary endpoints include Overall Survival (OS), response rates, and quality of life.

Nanobiotix expects a futility analysis at 18 months and an interim readout 30 months after the first patient is randomized. NANORAY-312 builds on Nanobiotix Study 102, a phase I trial evaluating safety and early signs of efficacy for radiotherapy-activated NBTXR3 in high-risk elderly LA-HNSCC patients who are chemotherapy-ineligible and intolerant to cetuximab. Preliminary data presented at the 2021 Annual Meeting of the American Society for Radiation Oncology (ASTRO) showed that the treatment was feasible and well tolerated at all dose levels.

Exploratory efficacy data showed a high target lesion objective response rate of 85.4% and a target lesion complete response rate of 63.4%, along with a median PFS of 10.6 months and median OS of 18.1 months in the evaluable patient population, which has a poorer prognosis than those patients eligible for the phase III study. The U.S. Food and Drug Administration (FDA) has granted Fast Track designation for the investigation of radiotherapy-activated NBTXR3 in the NANORAY-312 population, which includes the opportunity for Priority Review and Accelerated Approval. NBTXR3 is a novel, potentially first-in-class oncology product composed of functionalized hafnium oxide nanoparticles that is administered via one-time intratumoral injection and activated by radiotherapy.

The product candidate's physical mechanism of action (MoA) is designed to induce significant tumor cell death in the injected tumor when activated by radiotherapy, subsequently triggering adaptive immune response and long-term anti-cancer memory. Given the physical MoA, Nanobiotix believes that NBTXR3 could be scalable across any solid tumor that can be treated with radiotherapy and across any therapeutic combination, particularly immune checkpoint inhibitors. NBTXR3 is being evaluated in locally advanced head and neck squamous cell carcinoma (HNSCC) as the primary development pathway.

The company-sponsored phase I dose escalation and dose expansion study has produced favorable safety data and early signs of efficacy. In February 2020, the United States Food and Drug Administration granted regulatory Fast Track designation for the investigation of NBTXR3 activated by radiation therapy, with or without cetuximab, for the treatment of patients with locally advanced HNSCC who are not eligible for platinum-based chemotherapy. Nanobiotix has also prioritized an Immuno-Oncology development program—beginning with a Company sponsored phase I clinical study evaluating NBTXR3 activated by radiotherapy in combination with anti-PD-1 checkpoint inhibitors for patients with locoregional recurrent or recurrent/metastatic HNSCC and lung or liver metastases from any primary cancer eligible for anti-PD-1 therapy either naïve or resistant to prior PD-1 (either primary or secondary as per SITC criteria).

Given the Company's focus areas, and balanced against the scalable potential of NBTXR3, Nanobiotix has engaged in strategic collaborations with world class partners to expand development of the product candidate in parallel with its priority development pathways. Pursuant to this strategy, in 2019 Nanobiotix entered into a broad, comprehensive clinical research collaboration with The University of Texas MD Anderson Cancer Center to sponsor several phase I and phase II studies to evaluate NBTXR3 across tumor types and therapeutic combinations. In 2021, the Company entered into an additional strategic collaboration agreement with LianBio to support its global phase III study in Asia along with four future registrational studies.