Functional Characterization of CFI-400945, a Polo-like Kinase 4 Inhibitor, as a Potential Anticancer Agent

• CFI-400945 is a PLK4 small molecule inhibitor with significant anticancer activity
• CFI-400945 causes dysregulated centriole duplication, mitotic errors, and cell death
• CFI-400945 may represent a therapeutic option for a range of solid tumors

SummaryPLK4 was identified as a promising therapeutic target through a systematic approach that combined RNAi screening with gene expression analysis in human breast cancers and cell lines. A drug discovery program culminated in CFI-400945, a potent and selective PLK4 inhibitor. Cancer cells treated with CFI-400945 exhibit effects consistent with PLK4 kinase inhibition, including dysregulated centriole duplication, mitotic defects, and cell death. Oral administration of CFI-400945 to mice bearing human cancer xenografts results in the significant inhibition of tumor growth at doses that are well tolerated. Increased antitumor activity in vivo was observed in PTEN-deficient compared to PTEN wild-type cancer xenografts. Our findings provide a rationale for the clinical evaluation of CFI-400945 in patients with solid tumors, in particular those deficient in PTEN.