Abstract 1532P
Background
About 60% of the pancreatic cancers were diagnosed with metastasis and lose surgery opportunity. PD-1 inhibitors have shown a significant efficacy in enhancing anti-tumor immune response in most solid tumors. This retrospective study aimed to explore the efficacy and safety of nab-paclitaxel plus S1 combined with sintilimab, a PD-1 inhibitor, as first-line treatment of metastatic pancreatic ductal adenocarcinoma (mPDAC).
Methods
Patients with mPDAC who have never received anti-tumor therapy before were enrolled in this study. Treatment for patients in group A consisted of nab-paclitaxel 120 mg/m2 intravenously on days 1 and 8; S-1 80 mg/m2 orally on days 1 to 14 cycled every 3 weeks; treatment for patients in group B was the same as that for patients in group A, and added sintilimab 200 mg intravenously, once every 3 weeks. Surgery was operated when a complete or major radiological response of the liver metastases was overserved. The primary end point was progression-free survival (PFS). Secondary end points were resection rate, overall response rate (ORR), disease control rate (DCR), overall survival (OS) and safety.
Results
From 2017 to 2019, 65 mPDAC unselected patients were included in this study, 34 patients in group A and 31 patients in group B. ORR for group A was 44.1% and 58.1% for group B. DCR was 79.4% for group A and 96.8% for group B (P =0.01). Radical resection was carried out in 14 (21.5%) patients after downstaging of mPDAC, 4 (11.8%) in group A and 10 (32.2%) in group B (P =0.045), altogether 3 (8.8%) patients in group A and 8 (25.8%) in group B achieving R0 (P =0.07). Two patients in group B achieved a complete response (CR). Median PFS was 9.7 months for group A and 10.1 months for group B (P =0.01). Median OS for group A was 15.5 months and was not achieved for group B (P =0.03). The most common adverse events of grade 3 to 4 were neutropenia (32.4% in group A vs. 38.7% in group B), sensory neuropathy (8.8% in group A vs. 9.7% in group B), and elevated AST/ALT (5.9% in group A vs. 12.9% in group B).
Conclusions
Compared with undergoing nab-paclitaxel plus S1 alone, combined with sintilimab showed significantly improved DCR, PFS and OS and a favorable safety profile in mPDAC patients.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
X. Li, T. Ma: Full/Part-time employment: Genetron Health (Beijing) Co. Ltd. All other authors have declared no conflicts of interest.