Recommended Dose for Planned Registrational Study of NBTXR3 Plus Anti-PD-1 for Patients With mSCCHN Resistant to Prior Immunotherapy Established

The combined dose escalation and dose expansion parts of Study 1100 are expected to enroll up to 141 patients. The complete dose escalation part enrolled 29 patients in three cohorts: (i) head and neck lesions from LRR or R/M HNSCC eligible for anti-PD-1 therapy; (ii) lung mets from any primary cancer eligible for anti-PD-1 therapy; and (iii) liver mets from any primary cancer eligible for anti-PD-1 therapy. Study participants received a one-time intratumoral injection of NBTXR3 prior to their first radiotherapy session. They then received radiotherapy, followed by anti-PD-1. Based on the study’s results, the RP2D for all three cohorts was determined to be 33% of gross tumor volume.