Adjuvant 131I-metuximab for hepatocellular carcinoma after liver resection: a randomised, controlled, multicentre, open-label, phase 2 trial

Background Effective adjuvant treatment after hepatectomy for hepatocellular carcinoma (HCC) is an important area of research. Radioactive iodine (I-131)-labelled metuximab is a radiolabelled monoclonal antibody against the CD147 (also known as basigin or HAb18G) antigen that is expressed in HCC. We aimed to examine the role of I-131-metuximab as an adjuvant therapy after HCC resection. Methods This randomised, controlled, multicentre, open-label, phase 2 trial was done at five medical centres in China. Patients aged 18-75 years who underwent curative-intent resection of histologically confirmed HCC expressing CD147 were randomly assigned (1:1) by a computer-generated random sequence, stratified by centre, to receive either adjuvant transarterial injection of one dose of 27.75 MBq/kg I-131-metuximab 4-6 weeks after the hepatectomy (treatment group) or no adjuvant treatment (control group). Patients and physicians were not masked to the study groups. The primary outcome was 5-year recurrence-free survival (RFS) in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT00819650. Findings Between April 1, 2009, and Nov 30, 2012, 485 patients were screened for eligibility. 329 (68%) of these patients were excluded and 156 (32%) were randomly assigned to receive either I-131-metuximab (n=78) or no adjuvant treatment (n=78). The median follow-up was 55.9 months (IQR 18.6-79.4). In the intention-to-treat population, the 5-year RFS was 43.4% (95% CI 33.6-55.9) in the I-131-metuximab group and 21.7% (14.2-33.1) in the control group (hazard ratio 0.49 [95% CI 0.34-0.72]; Z=2.96, p=0.0031). I-131-metuximab-associated adverse events occurred within the first 4 weeks in 34 (45%) of 76 patients, seven (21%) of whom had grade 3 or 4 adverse events. These adverse events were all resolved with appropriate treatment within 2 weeks of being identified. Interpretation Adjuvant I-131-metuximab treatment significantly improved the 5-year RFS of patients after hepatectomy for HCC tumours expressing CD147. This treatment was well tolerated by patients. Copyright (C) 2020 Elsevier Ltd. All rights reserved.