Clinical Outcomes of Gemcitabine Plus Nab-Paclitaxel-Based Chemoradiotherapy in a Multidisciplinary Treatment Strategy for Locally Advanced Pancreatic Cancer (NUPAT-05): A Prospective, Single-Arm, Phase II Study.

Abstract

Although chemoradiotherapy (CRT) has exhibited activity against locally advanced pancreatic cancer (LAPC), no standard regimen has been established. We previously completed a Phase I trial of CRT with gemcitabine plus nab-paclitaxel (GnP) and established the recommended dose. This prospective, single-arm, Phase II study evaluated the safety and efficacy of GnP-based CRT in patients with LAPC. They received the NUPAT-05 trial protocol treatment (UMIN000028116). Conversion surgery (CS) was considered for patients who achieved favorable local disease control and tumor markers normalization. To evaluate the efficacy of multidisciplinary treatment, the primary endpoint was the 2-year overall survival (OS) rate, with a predefined threshold of 15%, and the key secondary endpoint was the CS rate. The other secondary endpoints included OS, progression free survival (PFS), time to treatment failure (TTF), and adverse events. Twenty-five patients were enrolled in the trial. The 2-year OS rate was 36.0%, meeting the primary endpoint. The CS rate was 32.0%, and the 2-year OS rate reached 75.0% among patients who underwent CS. Postoperative major complications occurred in 37.5% of patients. The median OS, PFS, and TTF were 20.8, 13.8, and 7.9 months, respectively. Although adverse events (Grade ≥ 3) occurred in 92.0% of patients, no treatment-related Grade 5 events occurred. In conclusion, our findings suggested that GnP-based CRT showed encouraging clinical activity with manageable toxicity in patients with LAPC. Future studies are needed to validate the additional benefits of radiotherapy. Trial Registration: UMIN-CTR: UMIN000028116.