ATN-161 is a novel integrin α5β1 antagonist that inhibits angiogenesis and growth of liver metastases in a murine model.

The combination of ATN-161 plus 5-FU significantly reduces tumor cell proliferation compared to control and single-agent therapy. In addition, combination therapy leads to a significant increase of apoptotic (TUNEL-positive) tumor cells, whereas single-agent therapy does not increase in TUNEL-positive tumor cells. ATN-161 treatment leads to a significant reduction in EC number (21% decrease) after a 48 hr incubation time compared to control [1]. ATN-161 inhibits VEGF-induced migration and capillary tube formation in hCECs, but did not inhibit proliferation. ATN-161 decreases the number of cells migrating in response to VEGF in a dose-dependent manner starting at 100 nM (P<0.001 vs. VEGF group) [2].

The preliminary experiments with α5β1-negative human colon cancer xenografts (HT29) show that treatment with ATN-161 significantly reduces tumor weight and vessel density [1]. Injection of ATN-161 after laser photocoagulation inhibits choroidal neovascularization (CNV) leakage and neovascularization to an extent similar to AF564 [2].