Assessing NBTXR3 in R/M HNSCC: The Design of Study 1100

In an interview with Targeted Oncology, Colette Shen, MD, PhD, assistant professor at the University of North Carolina (UNC) Chapel Hill and radiation oncologist at the UNC Lineberger Comprehensive Cancer Center, provides an overview of the design of Study 1100 (NCT03589339) assessing the safety and preliminary efficacy of NBTXR3 (JNJ-1900), a novel radiotherapy-enhancing agent, in recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

Watch part 1 and part 2 of Dr Shen’s interview.

Study 1100 was a phase 1, non-randomized study consisting of dose-escalation and dose-expansion portions which enrolled patients with R/M HNSCC. Patients were included if they had previous anti–PD-1 therapy and developed primary resistance to the therapy (ie, anti–PD-1 non-responder) or did not have previous anti–PD-1 therapy (ie, anti–PD-1 naive).¹

The objective of the dose-escalation portion was to determine the recommended dose of NBTXR3 to be administered to patients in the subsequent dose-expansion portion. This was achieved by starting with lower doses and increasing to higher doses, eventually establishing a recommended dose of 33% volume within the tumor.

With the established recommended dose, the dose-expansion portion aimed to measure the safety of the agent—specifically, the incidence of grade 3 and higher treatment-related adverse events—as well as antitumor response and pharmacokinetic profile. In this portion, patients received a 1-time injection to 1 tumor on the first day of study treatment. About 1 to 2 weeks after the injection, patients underwent stereotactic body radiation therapy (SBRT) for 3 to 5 sessions. Following radiation completion, patients started anti–PD-1 therapy, which continued for as long as responses were elicited without toxicities, up to 24 months.¹

Read the full interview here.

REFERENCE:

1. NBTXR3 activated by radiotherapy for patients with advanced cancers treated with an anti-PD-1 therapy. ClinicalTrials.gov. Updated January 14, 2025. Accessed October 9, 2025. https://clinicaltrials.gov/study/NCT03589339