A selective NVL inhibitor suppresses tumor growth by targeting ribosome biogenesis.

Ribosome biogenesis is highly upregulated in cancer and essential for malignant growth, yet efforts to selectively target this process pharmacologically have been unsuccessful. Here we identify nuclear valosin-containing protein-like (NVL), a hexameric AAA+ ATPase required for large ribosomal subunit (60S) assembly, as a druggable target in this pathway. Using forward genetics, we discovered that the cytotoxic dibenzothiazepinone MM17 inhibits NVL. Mutations conferring resistance to MM17 in cancer cells also rendered recombinant NVL refractory to enzymatic inhibition in vitro, providing convergent genetic and biochemical evidence of target engagement. Cryo-electron microscopy structures revealed two MM17-binding sites within the NVL hexamer, with resistance mutations clustering around the ligand pocket. NVL inhibition disrupts 60S biogenesis and activates p53 without inducing DNA damage. A more potent, bioavailable analog, MM927, recapitulates these effects and suppresses tumor growth in vivo without detectable toxicity. These findings establish NVL inhibitors as first-in-class therapeutics targeting ribosome biogenesis in cancer.