The antitumor effect of the angiogenesis inhibitor TNP470, O-(chloro-acetyl-carbamoyl) fumagillol, a synthetic analogue of fumagillin, was studied in vitro and in vivo on, cell line KB which produced interleukin (IL)-8. In vitro, TNP470 reduced the production of IL-8 from KB cells, the same as anti-IL-8 antibody (Ab.) The combination of anti-IL-8 Ab (10 micrograms/ml) and TNP470 (10 ng/ml) significantly inhibited the proliferation of KB cells, compared to no treatment (p < 0.05). Proliferation of KB cells was also significantly more suppressed by simultaneous treatment of cisplatin and TNP470 (1 mg/ml), than cisplatin alone. The in vivo antitumor effect of TNP470 was studied using anti-IL-8 Ab, anti-vascular endothel growth factor (VEGF) Ab, and TNP470, in administered by different routes, i.e., intratumoral (i.t.), intraperitoneal (i.p.), and intravenous. TNP470 (10 mg/ml) showed an antitumor effect, and intratumoral administration of TNP470 was the most effective route. Combined administration of anti-IL-8 Ab (i.p.) and TNP470 (i.t.) reduced tumor volume more than anti-IL-8 Ab alone did. These results suggest that the combination of TNP470, cisplatin, and anti-IL-8 Ab could be a beneficial treatment for solid tumors of the head and neck.