A phase Ib/II trial of PEP503 (NBTXR3, radioenhancer) with radiotherapy and chemotherapy in patients with rectal cancer

Aims: To investigate the safety profile, dose-limiting toxicity and antitumor activity of PEP503 (NBTXR3) nanoparticles with radiotherapy and concurrent chemotherapy in patients with locally advanced or unresectable rectal cancer.Methods: Patients will receive a single intratumoral injection of the nanoparticles, followed by radiotherapy and intravenous infusion of fluorouracil or oral capecitabine concurrently. In phase Ib (escalation phase, 3 + 3 design), volume escalation is based on the tumor volume of 5%, 10%, 15% and 22% of total baseline tumor volume. In phase II (expansion phase), 18 additional patients will be enrolled.Discussion: This study will be the first prospective, open-label, single-arm, nonrandomized study to investigate the efficacy and safety profile of PEP503 (NBTXR3) nanoparticles with radiotherapy and chemotherapy in these patients.

Automated summary

This study aims to investigate the safety profile, dose-limiting toxicity, and antitumor activity of PEP503 (NBTXR3) nanoparticles with radiotherapy and chemotherapy in patients with locally advanced or unresectable rectal cancer. Patients will receive a single intratumoral injection of the nanoparticles, followed by radiotherapy and concurrent intravenous infusion of fluorouracil or oral capecitabine. The study design includes an escalation phase and an expansion phase to determine the efficacy and safety of this treatment approach.