Vorinostat suppressed tumor growth in nude mice xenografts. 5 × 106 MES-SA cells were injected subcutaneously in Nude-Foxn1nu/nu mice (n = 14) and four days later mice were injected either placebo (HOP-β-CD) or 50 mg/kg/day vorinostat dissolved in HOP-β-CD for a total of 21 days. (a) The mice weight curve was stable during the whole treatment indicating that no cachexy was induced by tumor growth. (b) Two representative xenograft mice from each placebo and vorinostat-treated group are shown. Tumors were isolated and tumor weight and volume were determined. In most cases tumors were monolobular, whereas only in two mice two tumor nodules were found at injection side. Obvious differences in tumor volumes were observed between the placebo (2304.7 mm3) versus the vorinostat-treated group (1135.4 mm3). (c) These differences were statistically highly significant at the end of treatment (P = 0.044).