Enhancing effect of bromovinyldeoxyuridine on antitumor activity of 5-fluorouracil and ftorafur against adenocarcinoma 755 in mice.

When combined with bromovinyldeoxyuridine (BVdUrd), 5-fluorouracil (FUra) brought about a significant reduction in the growth of adenocarcinoma 755 tumors in mice, at doses at which either drug used alone (BVdUrd: 100 mg/kg) did not effect an appreciable antitumor activity. BVdUrd also increased the toxicity of FUra for the hosts but not commensurately with its enhancing effect on the antitumor activity of FUra. BVdUrd also potentiated the antitumor activity of ftorafur, so that doses of ftorafur (50 or 100 mg/kg) which by themselves did not cause a significant reduction in tumor growth became markedly effective when combined with BVdUrd at a dose as low as 10 mg/kg. For some combinations of BVdUrd with FUra, the antitumor potency was further enhanced by the administration of L-cysteine (300 mg/kg).