Tiragolumab in combination with atezolizumab and bevacizumab in patients with unresectable, locally advanced or metastatic hepatocellular carcinoma (MORPHEUS-Liver): a randomised, open-label, phase 1b–2, study

PD-L1 and VEGF blockade with atezolizumab plus bevacizumab has been shown to improve survival in unresectable hepatocellular carcinoma. TIGIT is an immune checkpoint regulator implicated in many cancers, including unresectable hepatocellular carcinoma. Here, we evaluate the clinical activity and safety of the addition of tiragolumab, an anti-TIGIT monoclonal antibody, to atezolizumab plus bevacizumab.

This randomised, open-label, phase 1b-2 umbrella study was conducted at 26 centres across China, France, Israel, New Zealand, South Korea, Taiwan, and the USA. Eligible patients were adults aged 18 years old or older with previously untreated locally advanced unresectable hepatocellular carcinoma, an Eastern Cooperative Oncology Group performance status of 0-1, Child-Pugh class A disease, and a life expectancy of at least 3 months. Eligible patients were randomly assigned (2:1) using permuted block randomisation to receive either tiragolumab 600 mg plus atezolizumab 1200 mg plus bevacizumab 15 mg/kg or atezolizumab 1200 mg plus bevacizumab 15 mg/kg, administered via intravenous infusion every 3 weeks on day 1 of each 21-day cycle. Patients received treatment until unacceptable toxic effects or loss of clinical benefit, whichever occurred first. The primary endpoint was objective response rate. Analysis of clinical activity was done in the efficacy-evaluable population (all patients who received at least one dose of each drug for their assigned treatment regimen) and safety was assessed in all patients who received any study treatment. The trial is registered with ClinicalTrials.gov, NCT04524871, and is ongoing.