A phase 1/2a trial of yttrium-90 radioembolization in combination with durvalumab for locally advanced unresectable hepatocellular carcinoma.

Abstract

Synergistic effect of radiotherapy and immunotherapy for the treatment of hepatocellular carcinoma (HCC) has been reported. This phase 1/2a pilot trial evaluated preliminary efficacy and safety of combination of radioembolization with yttrium-90 microspheres (Y90-radioembolization) and durvalumab in patients with locally advanced unresectable HCC. Patients with Child-Pugh score ≤7 and locally advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B HCC or BCLC-C disease without extrahepatic metastases, received Y90-radioembolization followed by intravenous durvalumab 1500 mg 7-14 days after Y90-radioembolization and every 4 weeks thereafter. Primary endpoint was time to progression (TTP) assessed by modified RECIST (mRECIST). Secondary endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR) determined by mRECIST, and safety. All 24 patients enrolled received Y90-radioembolization and 23 received at least one dose of durvalumab. Median follow-up duration was 19.0 months (range, 2.2-24.2). Median TTP was 15.2 months (95% confidence interval [CI], 6.1-not estimated). Median OS was not reached and 18-month OS rate was 58.3% (95% CI, 36.4-75.0). Median PFS was 6.9 months (95% CI, 5.4-15.2). Seven (29.2%) patients had a complete response and 13 (54.2%) had a partial response; ORR was 83.3% (95% CI, 62.6-95.3). Eleven (47.8%) patients experienced any-grade treatment-related adverse events. Two (8.7%) patients had grade 3 treatment-related adverse events (neutropenia and fever). None experienced any treatment-related serious adverse events. In patients with locally advanced unresectable HCC, the combination of Y90-radioembolization and durvalumab demonstrated promising efficacy and safety, warranting further evaluation in large-scale controlled trials.