A phase II study of YM 881 (zinostatin stimalamer) to determine the response and safety was conducted in patients with hepatocellular carcinoma by injecting a suspension of the drug into the hepatic artery. Repeated doses of 4 to 6 mg of the drug were given every 4 weeks so that the tumor tissues were filled with the suspension. Of the 195 registered patients, 15 were ineligible for the study, 8 dropped out, and data were missing for 5. A total of 167 patients completed the study. Response was assessed in the 167 patients who completed the study. CR was found in one, PR in 59, MR in 25, NC in 67, and PD in 15, with a response rate of 35.9. The safety of the drug was assessed in 177, excluding ineligible patients and 3 who dropped out because of the concurrent use of other drugs. Adverse reactions were found in 93.2% of the patients, and abnormal values in clinical laboratory tests in 60.5%. Major unwanted symptoms included fever, nausea, vomiting, and anorexia. Major abnormal changes in laboratory tests were elevated total bilirubin and LDH and abnormal hepatic function. About half the patients had malaise and pain related to the intra-arterial infusion therapy. The one year survival rate was 56.9%, and the duration of survival of 50% of the patients was 407 days.