AVN944 is a selective, noncompetitive inhibitor of inosine-5''-monophosphate dehydrogenase (IMPDH; Ki = 6-10 nM for both human IMPDH isoforms), a rate-limiting enzyme involved in the de novo synthesis of purine nucleotides. Inhibition of IMPDH results in disruption of DNA and RNA synthesis, inhibition of cell proliferation, and the induction of apoptosis. AVN944 has been shown to inhibit the proliferation of multiple myeloma cells in vitro by inducing caspase-independent apoptosis. It is also reported to have antitumor properties in androgen-sensitive and androgen-independent prostate cancer cells in vitro.
