– (Rac)-Tanomastat ((Rac)-BAY 12-9566) is a racemate of Tanomastat. Tanomastat (BAY 12-9566) is an orally active zinc carboxy-containing inhibitor of non-peptide biphenyl matrix metalloproteinases (MMPs) and inhibits MMP-2 (Ki: 11 nM), MMP-3 (Ki: 143 nM), MMP-9 (Ki: 301 nM), and MMP-13 (Ki: 1470 nM). In several experimental tumor models, Tanomastat exhibits anti-invasive and anti-metastatic effects.