Safety and Efficacy of 166ho Radioembolization in Hepatocellular Carcinoma: the HEPAR Primary Study.

The safety and efficacy of 166Ho radioembolization was first deter-mined in the HEPAR and HEPAR II studies, which, however, excluded patients with hepatocellular carcinoma (HCC). The aim of this prospec-tive clinical early phase II study was to establish the toxicity profile of 166Ho radioembolization in patients with measurable, liver-dominant HCC; Barcelona clinic liver cancer stage B or C; a Child-Pugh score of no more than B7; and an Eastern Cooperative Oncology Group perfor-mance status of 0-1 without curative treatment options. Methods: The primary endpoint was a rate of unacceptable toxicity defined as grade 3 hyperbilirubinemia (Common Terminology Cancer Adverse Events, version 4.03) in combination with a low albumin or ascites level in the absence of disease progression or treatment-related serious adverse events. Secondary endpoints included overall toxicity, response, sur-vival, change in a-fetoprotein, and quality of life. Thirty-one patients with Barcelona clinic liver cancer stage B (71%) or C (29%) HCC were included, mostly multifocal (87%) or bilobar (55%) disease. Results: Common grade 1 or 2 clinical toxicity included fatigue (71%), back pain (55%), ascites (32%), dyspnea (23%), nausea (23%), and abdom-inal pain (23%), with no more than 10% grade 3-5 toxicity. Grade 3 laboratory toxicity (>10%) included an aspartate transaminase and y-glutamyltransferase increase (16%), hyperglycemia (19%), and lym-phopenia (29%). Treatment-related unacceptable toxicity occurred in 3 of 31 patients. At 3 mo, 54% of target lesions showed a complete or partial response according to modified RECIST. Median overall sur-vival was 14.9 mo (95% CI, 10.4-24.9 mo). No significant changes in quality of life or pain were observed. Conclusion: The safety of 166Ho radioembolization was confirmed in HCC, with less than 10% unac-ceptable toxicity. Efficacy data support further evaluation.