STAT3 inhibitor OPB-31121

An orally bioavailable inhibitor of signal transducer and activator of transcription 3 (STAT3), with potential antineoplastic activity. OPB-31121 inhibits the phosphorylation of STAT3, which prevents binding of STAT3 to DNA sequences on a variety of STAT3-responsive promoters and may result in the inhibition of STAT3-mediated transcription and, potentially, the inhibition of tumor cell proliferation. STAT3 is constitutively activated in a variety of cancers, contributing to the loss of cell growth control and neoplastic transformation.