The PLK4 inhibitor RP-1664 demonstrates potent single-agent efficacy in neuroblastoma models through a dual mechanism of sensitivity

It was recently shown that inhibition of polo-like kinase 4 (PLK4) induces TP53 -dependent synthetic lethality in cancers with chromosome 17q-encoded TRIM37 copy number gain due to cooperative regulation of centriole duplication and mitotic spindle nucleation. We show here that chromosome 17q/TRIM37 gain is a pathognomonic feature of high-risk neuroblastoma and renders patient-derived cell lines hypersensitive to the novel PLK4 inhibitor RP-1664. We demonstrate that centriole amplification at low doses of RP-1664 contributes to this sensitivity in a TRIM37 - and TP53 -independent fashion. CRISPR screens and live cell imaging reveal that upon centriole amplification, neuroblastoma cells succumb to multipolar mitoses due to an inability to cluster or inactivate supernumerary centrosomes. RP-1664 showed robust anti-tumor activity in 14/15 neuroblastoma xenograft models and significantly extended survival in a transgenic murine neuroblastoma model. These data support biomarker-directed clinical development of PLK4 inhibitors for high-risk neuroblastoma and other cancers with somatically acquired TRIM37 overexpression.