Abstract Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the United States with extremely poor prognosis. Gemcitabine (Gem), the standard of care agent over the past 15 years, has limited clinical benefits. There is an urgent requirement for novel therapeutic strategies to improve overall survival of patients with pancreatic cancer. Angiogenesis, an essential process for tumor growth and metastasis, remains a sensible target for PDAC therapy. VEGF, PDGF, FGF and their receptors are all overexpressed and have been correlated with poor prognosis in human PDAC. Nintedanib (BIBF 1120, Nin) is a triple angiokinase inhibitor that targets VEGFR1/2/3, FGFR1/2/3 and PDGFRα/β signaling. Nintedanib is currently under clinical investigation for several solid tumors. The present study investigated the combination treatment benefits of gemcitabine and nintedanib in experimental PDAC. Cell proliferation, migration and protein expression were analyzed by WST-1 assay, wound healing assay and Western blotting. Tumor growth and animal survival experiments were performed in murine xenografts. Percent inhibition of cell proliferation in the Gem, Nin and Gem+Nin groups was 22%, 25% and 53% (AsPC-1 PDAC cells, Gem 50 nM, Nin 100 nM); 55%, 11% and 80% (endothelial cells HUVECs, Gem 100 nM, Nin 100 nM); 91%, 68% and 94% (fibroblast WI-38 cells, Gem 100 nM, Nin 100 nM). Nintedanib increased apoptosis, indicated by the cleavage of caspase-3 protein in all three cell-types tested. In PDAC cells, antitumor activity was accompanied by higher level of cell cycle inhibitor protein p27. Nintedanib (10 μM) inhibited in vitro wound closure by 84% in endothelial cells. In a heterotopic PDAC model, compared to the percent net local tumor growth in controls (100±29), a reduced growth of 60.8±10.5 (p=0.02) was observed in the Gem group, while a net reduction of -2.1±9.9 (p=0.0001) and -12.4±16.2 (p=0.0001) was observed in Nin and Gem+Nin groups, respectively. Compared with controls (16 days) in an AsPC-1 intraperitoneal model, median animal survival in Gem, Nin and Gem+Nin treatment groups was 25 days, 31 days and 38 days. The strong antitumor activity of nintedanib in experimental PDAC supports the potential of nintedanib-controlled mechanisms as targets for improved clinical PDAC therapy. Citation Format: Niranjan Awasthi, Stefan Hinz, Rolf A. Brekken, Margaret A. Schwarz, Roderich E. Schwarz. Antitumor activity of nintedanib (BIBF 1120), a triple angiokinase inhibitor, in combination with gemcitabine in experimental pancreatic cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1025. doi:10.1158/1538-7445.AM2014-1025