The use of intratumoral radioenhancer nanoparticle NBTXR3 in head and neck cancer

A new nonrandomized clinical trial published on JAMA Otolaringology – Head & Neck Surgery shows promising activity for the radioenhancer nanoparticle NBTXR3 followed by radiotherapy in patients with head and neck squamous cell carcinoma with limited treatment options.

The study was a single-arm, phase 1 dose-expansion nonrandomized clinical trial involving 56 patients with locally advanced head and neck squamous cell carcinoma; they were ineligible for cisplatin and cetuximab and received a single intratumoral administration of NBTXR3 in the primary tumor followed by radiotherapy. Objective tumor response was assessed in 44 patients and after a median follow-up of 33 months, objective response rate of the injected primary tumor and objective response rate of all lesions were 82% and 80%, respectively; among all 56 treated patients, the median progression-free survival was 11.4 months, and the median overall survival was 18.1 months. These results, as authors point out, «appeared favorable in the context of historical data of radiotherapy alone in older patients with locally advanced head and neck squamous cell carcinoma (where progression free survival is approximately 9 months and overall survival is approximately 12 months). Moreover, historical data did not distinguish cisplatin eligibility and only 30% of patients included had significant comorbidities, whereas the present study involved patients with a much poorer prognosis. This phase 1 dose-expansion nonrandomized clinical trial confirms the feasibility of NBTXR3 followed by radiotherapy in locally advanced head and neck squamous cell carcinoma patient population ineligible to cisplatin and cetuximab while also highlighting the need for improving patient selection related to the inherent challenges of treating a frail population with competing risks for mortality. Despite these challenges, when evaluating all patients enrolled into this study compared with historical controls of RT alone, there is a preliminary signal in efficacy that warrants further evaluation», authors conclude.