Proton Radiotherapy Plus Tremelimumab/Durvalumab for BCLC Stage B and C HCC

Tremelimumab plus durvalumab (STRIDE regimen) is an approved first-line therapy for unresectable hepatocellular carcinoma (HCC), yet it shows limited efficacy with an ORR of only 20.1%. Proton radiotherapy (RT), known for its precision and tissue-sparing advantages, has demonstrated improved survival outcomes and reduced toxicity compared to X-ray RT. Retrospective data suggest that combining proton RT with immune checkpoint inhibitors yields a promising ORR of 61.5%. Preclinical studies further support enhanced antitumor immunity when RT is combined with PD-L1 and CTLA-4 blockade. This phase II, single-arm clinical trial aims to evaluate the safety, efficacy, and immunologic effects of combining proton RT with tremelimumab and durvalumab in patients with unresectable HCC.