In vitro activity: Tasquinimod inhibits tumor angiogenesis by allosteric inhibition of HDAC4/N-CoR/HDAC3 dependent deacetylation of HIF-1α. Tasquinimod also targets infiltrating myeloid cells, and modulates local tumour immunity by blocking the interaction between S100A9 and its ligands receptor of advanced glycation end products and Toll-like receptor 4.

Kinase Assay: Tasquinimod binds to the regulatory Zn2+ binding domain of HDAC4 with Kd of 10-30 nM.

Cell Assay: Generated microarray data based on four separate biological replicates showed a drug-induced effect of 50μM tasquinimod on gene expression in LNCaP cells when cultured in vitro for 24 h. The expression data achieved by RT-PCR were consistent with the microarray analysis data with a significant up-regulation of THBS1, GDF15 and CYP1A1 whereas CXCR4 and AGER1 did not change expression significantly.