Photon Radiotherapy Combined With Tremelimumab and Durvalumab for BCLC Stage B and C Hepatocellular Carcinoma
Tremelimumab plus durvalumab (the STRIDE regimen) is an approved first-line therapy for unresectable hepatocellular carcinoma (HCC); however, it demonstrates limited efficacy, with an objective response rate (ORR) of only 20.1%. Radiation therapy (RT) is highly effective in controlling localized solid tumors and has become an integral component of the treatment algorithm for unresectable HCC. Preclinical studies have shown that combining RT with PD-L1/PD-1 blockade promotes immunogenic cell death and enhances antigen presentation by dendritic cells, thereby boosting systemic T cell-mediated antitumor responses in mouse models. The addition of CTLA-4 inhibition further enhances antigen cross-priming following RT. Recent retrospective data also indicate that combining RT with immune-oncology agents is associated with improved overall survival and prolonged time to progression compared to RT or immunotherapy alone. However, the clinical benefit and immunologic impact of combining RT with tremelimumab and durvalumab have not yet been evaluated in prospective clinical trials for unresectable HCC. This phase II, single-arm clinical trial aims to assess the safety, efficacy, and immunologic effects of combining proton RT with tremelimumab and durvalumab in patients with unresectable HCC.
• Participants must have diagnosis of HCC that is deemed unsuitable for surgical resection or transplant. Participants may have multiple lesions with a total maximal tumor dimension of \< 20 cm, and no one lesion \> 15 cm. Diagnosis should be confirmed by at least 1 criterion listed below:
‣ Histologically or cytologically proven diagnosis of HCC.
⁃ Typical arterial enhancement and delayed washout on multiphasic CT or MRI.
• Age ≥18 years at the time of signing informed consent document.
• ECOG performance status 0-1.
• Barcelona Clinic Liver Cancer (BCLC) stages Intermediate (B) or Advanced (C).
• Child-Pugh score 5-6 liver function within 28 days of study registration.
• Documented virology status of hepatitis B virus (HBV), as confirmed by screening HBV serology test.
• Documented virology status of hepatitis C virus (HCV), as confirmed by screening HCV serology test.
• Ability to understand and the willingness to sign a written informed consent document
• Adequate bone marrow, liver, and renal function within 4 weeks before study registration
‣ Hemoglobin ≥ 9.0 g/dL
⁃ Absolute neutrophil count (ANC) ≥ 1,000/mm3
⁃ Platelet count ≥ 50,000/μL
⁃ Total bilirubin \< 2.5 mg/dL
⁃ Serum albumin \>2.8 g/dL
⁃ Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 × upper limit of normal (ULN)
⁃ Prothrombin time ≤ 6 seconds prolonged
⁃ Serum creatinine ≤ 1.5 mg/dL