Randomized Phase II Study of Gemcitabine and S-1 Combination Therapy Versus Gemcitabine and Nanoparticle Albumin-Bound Paclitaxel Combination Therapy in Locally Advanced Pancreatic Ductal Adenocarcinoma (PDAC-GS/GA-rP2, CSGO-HBP-015)

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, and multimodal strategies, such as surgery plus neoadjuvant chemotherapy (NAC)/adjuvant chemotherapy, have been attempted to improve survival in patients with localized PDAC. To date, there is one prospective study providing evidence for the superiority of a neoadjuvant strategy over upfront surgery for localized PDAC. However, which NAC regimen is optimal remains unclear.Methods: A randomized, exploratory trial was performed to examine the clinical benefits of two chemotherapy regimens, gemcitabine plus S-1 (GS) and gemcitabine plus nab-paclitaxel (GA), as NAC for patients with planned PDAC resection. Patients were enrolled after the diagnosis of resectable or borderline resectable PDAC. They were randomly assigned to either NAC regimen. Adjuvant chemotherapy after curative resection was highly recommended for 6 months in both arms. The primary endpoint was tumor progression-free survival time, and secondary endpoints included the rate of curative resection, the completion rate of protocol therapy, the recurrence type, the overall survival time and safety. The target sample size was set as at least 100.Discussion: This study is the first randomized phase II study comparing GS combination therapy with GA combination therapy as NAC for localized pancreatic cancer.Trial registration: This trial began in April 2016 and was registered with the UMIN Clinical Trials Registry (UMIN000021484).