AIM To investigate the therapeutic potential of tesevatinib(TSV),a unique multi-kinase inhibitor currently in Phase Ⅱ clinical trials for autosomal dominant polycystic kidney disease(ADPKD),in well-defined rodent models of autosomal recessive polycystic kidney disease(ARPKD).METHODS We administered TSV in daily doses of 7.5 and 15 mg/kg per day by I.P.to the well characterized bpk model of polycystic kidney disease starting at postnatal day(PN) 4 through PN21 to assess efficacy and toxicity in neonatal mice during postnatal development and still undergoing renal maturation.We administered TSV by oral gavage in the same doses to the orthologous PCK model(from PN30 to PN90) to assess efficacy and toxicity in animals where developmental processes are complete.The following parameters were assessed:Body weight,total kidney weight;kidney weight to body weight ratios;and morphometric determination of a cystic index and a measure of hepatic disease.Renal function was assessed by:Serum BUN;creatinine;and a 12 h urinary concentrating ability.Validation of reported targets including the level of angiogenesis and inhibition of angiogenesis(active VEGFR2/KDR) was assessed by Western analysis.RESULTS This study demonstrates that:(1) in vivo pharmacological inhibition of multiple kinase cascades with TSV reduced phosphorylation of key mediators of cystogenesis:EGFR,ErbB 2,c-Src and KDR;and(2) this reduction of kinase activity resulted in significant reduction of renal and biliary disease in both bpk and PCK models of ARPKD.The amelioration of disease by TSV was not associated with any apparent toxicity.CONCLUSION The data supports the hypothesis that this multi-kinase inhibitor TSV may provide an effective clinical therapy for human ARPKD. AIM To investigate the therapeutic potential of tesevatinib (TSV), a unique multi-kinase inhibitor. In current Phase II clinical trials for autosomal dominant polycystic kidney disease (ADPKD), in well-defined rodent models of autosomal recessive polycystic kidney disease (ARPKD). METHODS We administered TSV in daily doses of 7.5 and 15 mg / kg per day by IP to the well characterized bpk model of polycystic kidney disease starting at postnatal day (PN) 4 through PN21 to assess efficacy and toxicity in neonatal mice during postnatal development and still undergoing renal maturation. We administer TSV by oral gavage in the same doses to the orthologous PCK model (from PN30 to PN90) to assess efficacy and toxicity in animals where developmental processes are complete. the following parameters were assessed: Body weight, total kidney weight; kidney weight to body weight ratios; and morphometric determination of a cystic index and a measure of hepatic disease. Renal function was assessed by: Serum BUN; c Resatinine; and a 12 h urinary concentrating ability. Scale of reported targets including the level of angiogenesis and inhibition of angiogenesis (active VEGFR2 / KDR) was assessed by Western analysis. RESULTS This study demonstrates that: (1) in vivo pharmacological inhibition of multiple kinase cascades with TSV reduced phosphorylation of key mediators of cystogenesis: EGFR, ErbB 2, c-Src and KDR; and (2) this reduction of kinase activity resulted in significant reduction of renal and biliary disease in both bpk and PCK models of ARPKD. The amelioration of disease by TSV was not associated with any apparent toxicity. CONCLUSION The data supports the hypothesis that this multi-kinase inhibitor TSV may provide an effective clinical therapy for human ARPKD.