131I-Labeled-Metuximab Plus Transarterial Chemoembolization in Combination Therapy for Unresectable Hepatocellular Carcinoma: Results from a Multicenter Phase IV Clinical Study

Objective: This study evaluated the safety and objective response of combining $^{131}I$-labeled-metuximab (Licartin) with transarterial chemoembolization (TACE) in the treatment of unresectable hepatocellular carcinoma (HCC). Materials and Methods: In a multicenter open-label clinical trial, 341 enrolled patients with stage III/IV HCC according to TNM criteria were nonrandomly assigned to a trial group (n=167) and a control group (n=174), undergoing TACE following hepatic intra-arterial injection of licartin or TACE alone from July 2007 to July 2009. Radiopharmaceutical distribution was evaluated. The primary endpoint was overall survival; secondary endpoints included time-to-progression (TTP), toxicity and adverse events (AEs). Results: The radiobiological distribution demonstrated better localization of licartin in liver tumors than other tissues (P<0.01). The organ absorbed doses to liver and red marrow were $3.19{\pm}1.01Gy$ and $0.55{\pm}0.22Gy$, respectively. The 1-year survival rate was significantly higher [79.47% vs. 65.59%, hazard ratio (HR), 0.598, P=0.041] and TTP significantly improved ($6.82{\pm}1.28$ vs. $4.7{\pm}1.14months$, P=0.037) compared with the control group. Patients at stage III achieved more benefit of one year survival than stage IV in the trial group (86.9% vs. 53.8%, P<0.001). There were significant different toxicities in leukocytopenia, thrombocytopenia and increased total bilirubin level [P<0.001, P=0.013, P<0.01, relative risk (RR) 1.63, 1.33, 1.43], but no differences in severe AEs of upper GI hemorrhage and severe liver dysfunction between the groups (5.39% vs. 2.3%, P=0.136). Conclusions: Owing to excellent tumor-targeting, promised efficacy and favourable toxicity profile, the novel combination therapy of licartin and TACE could be applied in patients with unresectable HCC.