FOLFIRINOX plus high intensity focused ultrasound for locally advanced/borderline resectable pancreatic ductal adenocarcinoma: A prospective single arm phase II trial.

Abstract

670 Background: FOLFIRINOX has been the standard regimen for locally advanced pancreatic cancer (LAPC) for palliation and borderline resectable pancreatic cancer (BRPC) for neoadjuvant treatment. According to the results of animal studies, concurrent use of high intensity focused ultrasound (HIFU) and chemotherapy can enhance the drug delivery to the target tissue. In this phase II trial, we aimed to evaluate the safety and therapeutic efficacy of FOLFIRINOX plus HIFU for patients with LAPC or BRPC. Methods: This study was designed as a prospective single center phase II trial (Study identifier: NCT05262452). We prospectively enrolled 60 patients (M:F=35:25; median age, 67.0 years old) with LAPC (n=23) or BRPC (n=37). The median tumor size was 4.0 cm (Interquartile range, 2.7-4.6). All patients were treated by FOLFIRINOX (oxaliplatin, 85mg/m2 of body-surface area; irinotecan, 180mg/m2; leucovorin, 400 mg/m2; and fluorouracil, 400 mg/m2 given as a bolus followed by 2400 mg/m2 given as a 46-hour continuous infusion) every 2 weeks until disease progression. HIFU was combined in the first 4 cycles of chemotherapy with following parameters: intensity of 2.0 kw/cm2, duty cycle of 1%, exposure time of 3 seconds and PRF of 10Hz. Follow-up contrast enhanced CT was taken every 4 cycles for the response evaluation using response evaluation criteria for solid tumor 1.1. Overall survival (OS) and progression-free survival were estimated using Kaplan-Meier method. All analyses were intention-to-treat. Results: Two patients withdrew the consent, and two patients could not complete planned 4 cycles of FOLFIRINOX plus HIFU treatment owing to sepsis from severe neutropenia related to chemotherapy. Among 56 patients who completed the 4 cycle of FOLFIRINOX plus HIFU and continued chemotherapy, partial response was achieved in 36 patients (60.0%, 36/60), and stable disease in 20 patients. Regarding the adverse effect (AE), 32 of 60 patients experienced grade 3 (n=22) or grade 4 (n=10) AE, all of them were related to FOLFIRINOX chemotherapy. No AE related to HIFU was observed. The estimated OS was 94.8%, 75.9% and 67.6% at 6-, 12- and 18 months, respectively. Regarding the PFS, the 6-, 12- and 18-month PFS was 91.9%, 70.3% and 56.2%, respectively. Conclusions: FOLFIRINOX plus HIFU was safe and effective treatment for LAPC/BRPC, providing 60.0% of partial response rate without any additional AE to chemotherapy. Clinical trial information: NCT05262452 .