BeiGene announced that the global Phase 3 RATIONALE 301 trial with tislelizumab met its primary endpoint of non-inferior Overall Survival (OS) versus sorafenib as a first-line treatment in adult patients with unresectable hepatocellular carcinoma (HCC). The safety profile for tislelizumab was consistent with previous studies and no new safety signals were reported. More than 600 patients in the U.S., Europe, and Asia participated in the study.

HCC is the sixth most common type of cancer worldwide, accounting for more than 900,000 new cases in 2020i, and despite improvements in screening, surveillance rules, and imaging, more than two-thirds of patients with HCC present with advanced disease at diagnosisi. RATIONALE 301 (NCT03412773) is a global, Phase 3, randomized, open-label study of tislelizumab compared with sorafenib as a first-line treatment in adult patients with unresectable HCC. The primary endpoint of the study is non-inferiority of OS between the two treatment groups.

The key secondary endpoint is Overall Response Rate, as assessed by Blinded Independent Review Committee (BIRC) per RECIST v1.1. Other secondary endpoints include other efficacy assessments such as Progression-Free Survival, Durability of Response, and Time to Progression per BIRC, as well as measures of health-related quality of life, and safety and tolerability. About Tislelizumab: Tislelizumab is a humanized IgG4 anti-PD-1 monoclonal antibody specifically designed to minimize binding to Fc-gamma (Fc?) receptors on macrophages, helping to aid the body's immune cells to detect and fight tumors. In pre-clinical studies, binding to Fc?

receptors on macrophages has been shown to compromise the anti-tumor activity of PD-1 antibodies through activation of antibody-dependent macrophage-mediated killing of T effector cells. Tislelizumab is the first drug from BeiGene's immuno-oncology biologics program and is being developed internationally as a monotherapy and in combination with other therapies for the treatment of a broad array of both solid tumor and hematologic cancers.