ATN-161 trifluoroacetate salt (ATN-161 TFA salt) is a novel integrin α5β1 antagonist that inhibits angiogenesis and growth of liver metastases and improves survival in a murine model.

The co-administration of ATN-161 and 5-FU markedly reduces tumor cell growth more effectively than either treatment alone or the control. Additionally, this combined approach markedly elevates the levels of apoptotic (TUNEL-positive) tumor cells, a result not observed with single-agent treatments. Furthermore, ATN-161 demonstrates a 21% reduction in endothelial cell (EC) numbers after 48 hours compared to controls, highlighting its effectiveness. Importantly, ATN-161 also impedes VEGF-induced endothelial cell migration and capillary formation, although it does not affect their proliferation. It significantly decreases endothelial cell migration towards VEGF in a dose-dependent manner, beginning at 100 nM (P<0.001 vs. VEGF group), showcasing its potential in inhibiting angiogenesis[1][2].

Initial tests on α5β1-negative human colon cancer xenografts (HT29) show ATN-161 significantly decreases tumor weight and vessel density [1]. Administering ATN-161 post-laser photocoagulation effectively suppresses choroidal neovascularization (CNV) leakage and new blood vessel formation, achieving results comparable to those with AF564 [2].