NBTXR3 With or Without I/O Shows Survival Benefit in Locally Advanced HNSCC

NBTXR3, an agent activated by radiotherapy, has demonstrated survival benefit in tough-to-treat elderly and frail patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC), according to a press release by Nanobiotix.

NBTXR3 is a first-in-class radioenhancer hafnium oxide nanoparticle that is activated by radiotherapy. It can be used both on its own or in combination with other immunotherapy agents. In 2020, NBTXR3 was granted a fast track designation from the FDA for the treatment of patients with LA-HNSCC who are not eligible for platinum-based chemotherapy.

In a phase 1 study, a single intratumor injection of NBTXR3 is being administered to patients with LA-HNSCC. The study has an estimated enrollment of 63 participants with an estimated study completion date of September 2022. Primary end points of the dose escalation portion include incidence of dose limiting toxicities and the recommended phase 2 dose. Secondary end points of the dose-escalation portion include objective response rate and complete response rate. Primary end points of the dose expansion portion include overall and complete response rates. Secondary end points of this phase include local progression-free survival (PFS) and PFS.

An analysis of 41 participants found that the median overall survival (OS) was 18.1 months in the tough-to-treat elderly and frail LA-HNSCC cohort. The median PFS was 10.6 months. The best observed target lesion objective response rate was 85.4% and the best observed target lesion complete response rate was 63.4%. In the overall population, the median OS was 14.1 months and the median PFS was 9.4 months. The treatment was found to be safe and well tolerated in a frail population with significant disease burden.

“I have held the belief that NBTXR3 could have a real impact for patients with solid tumors since reviewing the proof-of-concept data from the phase II/III in soft tissue sarcoma and throughout my participation in Study 102 Expansion,” said study principal investigator Christophe Le Tourneau, MD, PhD, senior medical oncologist and head of the Department of Drug Development and Innovation (D3i) at Institut Curie, in a press release. “This first look at survival data has added to my confidence that NBTXR3 could provide a promising new therapeutic option for the practice. I look forward to leading the upcoming phase 3 global registration study, and to have the opportunity to evaluate the promise of this innovation in a larger patient population.”

In order to participate in the study, patients must be 70 years of age or older or 65 years of age or older and unable to receive cisplatin. Patients also must have confirmed SCC of the oral cavity or oropharynx, no evidence of distant metastatic disease, adequate bone marrow function, adequate kidney function, and adequate liver function.

Patients with prior radiotherapy to any area within the planned radiotherapy field, tumor-related dyspnea, tumor ulceration, a history of stoke, non-measurable disease, uncontrolled intercurrent illness, or concurrent treatment with any other anticancer therapy are not eligible to participate.

In addition, the agent is being investigated across a number of different cancers, including pancreatic cancer, lung cancer, and esophageal cancer.

_REFERENCES:

_{Nanobiotix announces 18.1 month median overall survival for 41 evaluable elderly and frail patients with HNSCC in phase I expansion evaluating NBTXR3 as a single agent activated by radiotherapy. News release. Nanobiotix. October 24, 2021. Accessed October 26, 2021. https://bit.ly/3ElHMQX.}

_{NBTXR3 and radiation therapy in treating patients with locally advanced SCC of the oral cavity or oropharynx. ClinicalTrials.gov. Accessed October 26, 2021. https://bit.ly/3ElHPMD.}