Inactivation of the tumor suppressor p53 commonly coincides with increased signaling through NF-κB in cancer. CAY10681 is a dual modulator of p53-MDM2 interaction and NF-κB signaling. It potently binds MDM2 (Ki = 250 nM), reducing MDM2-mediated turnover of p53. CAY10681 also inhibits phosphorylation of IκBα and dose-dependently reduces nuclear accumulation of p65. It blocks the proliferation of cancer cell lines (IC50s range from 33 to 37 μM). CAY10681 exhibits excellent oral bioavailability and inhibits tumor growth in A549 xenografts in nude mice.