A) Representative MRI images showing the relative impact of vehicle (upper panel), cabozantinib (middle panel) and the c-MET inhibitor PF-04217903 (lower panels), on regression of established murine PTEN/p53 deficient prostate tumors. Mice were treated with the indicated drugs at the following concentrations: vehicle control, cabozantinib (100 mg/kg), PF-04217903 (50mg/kg). The yellow borders mark solid tumor boundaries during the 3-week course of treatment. B) Volumetric analysis showed significant tumor regression in mice treated with cabozantinib, but not vehicle or PF-04217903 treatment. C) H&E staining of tumors from cabozantinib-treated mice revealed near-complete eradication of poorly-differentiated prostate tumor at 4, 10, 18 and 21 days of treatment, not observed with vehicle- or PF-04217903-treated mice (n=4 mice per treatment arm/timepoint).