An orally bioavailable HDM2 antagonist with potential antineoplastic activity. Serdemetan inhibits the binding of the HDM2 protein to the transcriptional activation domain of the tumor suppressor protein p53. By preventing this HDM2-p53 interaction, the proteasome-mediated enzymatic degradation of p53 is inhibited, which may result in the restoration of p53 signaling and thus the p53-mediated induction of tumor cell apoptosis. HDM2 (human homolog of double minute 2), a zinc finger protein, is a negative regulator of the p53 pathway; often overexpressed in cancer cells, it has been implicated in cancer cell proliferation and survival.