Objectives: The aim of this study was to evaluate the response- and treatment-related toxicity for patients with unresectable hepatocellular carcinoma (HCC) treated with 131I-Hepama-1 mAb (DGDK-1).Materials and Methods: Seeking approval for the use of 131I-hepama-1 mAb, 32 patients with unresectable HCC were divided into 5 groups to take part in the Phase I clinical trial study. Systemic reactions and acute toxicity were evaluated weekly for at least 45 days following treatment with an intravenous injection of 10 mg of antibody radiolabeled with 740–3700 MBq (20–100 mCi), divided into 5 groups.Results: No patients demonstrated any evidence of fever, severe side effects, or impairments of important organs, such as the lung, liver, and heart. During, and for 45 days after, the treatment, most of their routine examinations of blood, functions of liver and kidneys, and the thyroid hormone were all normal. Hypothyroidism was not observed during the course of monitoring. None of the 32 patients developed human antimurine antibodies (HAMA) within 15 days of therapy; however, 82% of patients were HAMA-positive by 45 days of therapy. According to the pilot study of prognosis, survival from the start of radioimmunotherapy (RIT) was a median of 4 months, and the 1-year survival rate was 31%. The median survival time of 15 patients without metastases was 10 months, and the 1-year survival rate was 60%. Of alpha-fetoprotein (AFP)-positive patients, 75% of AFP levels decreased by at least 50% or became normal. Of all patients, 84% showed an improved Eastern Cooperative Oncology Group (ECOG) performance status. Conclusion: This phase I clinical trial demonstrated that it was safe to use 131I-hepama- 1 mAb by peripheral intravenous administration. The recommended dose of DGDK-1 for clinical use is 1480–2960 MBq/10mg.
