TD139 is an inhaled galectin-3 inhibitor (Kd: 14 nM).

TD139 has a high affinity for galectin-3 with a Kd of 14 nM and 10 nM for galectin-1, but low affinity for galectins 2, 4N, 4C, 7, 8N, or 9N [1].

In primary lung AECs TD139 reduces TGF-β1–induced β-catenin translocation to the nucleus, with most of the β-catenin remaining at the cell surface. TD139 blocks TGF-β1–induced β-catenin phosphorylation. A marked reduction in fibrosis and β-catenin activation accompanied by the decreased galectin-3 expression is observed in the lungs of WT mice treated with TD139 [1]. Pretreatment of WT C57BL/6 mice with TD139 leads to the attenuation of liver injury and milder infiltration of IFNγ- and IL-17- and -4-producing CD4(+) T cells, as well as an increase in the total number of IL-10-producing CD4(+) T cells and F4/80(+) CD206(+) alternatively activates macrophages and prevents the apoptosis of liver-infiltrating MNCs [2].