Innovent Biologics, Inc. announced that the first patient has been dosed in a phase III clinical trial (ORIENT-15) that is to evaluate Tyvyt (fully human anti-PD-1 therapeutic monoclonal antibody, generic name: sintilimab injection), in combination with paclitaxel and cisplatin, as first-line treatment in patients with advanced, recurrent or metastatic esophageal squamous cell carcinoma (ESCC). The ORIENT-15 study is a randomized, double-blind, multi-center, phase III trial conducted in China to evaluate the efficacy and safety of Tyvyt (sintilimab injection) or placebo in combination with chemotherapy as first-line treatment in subjects with unresectable, locally advanced, recurrent or metastatic ESCC. The phase III study will enroll 640 patients. The study follows a phase Ib study that evaluated Tyvyt (sintilimab injection) in patients with esophageal cancer and a phase II study that evaluated Tyvyt (sintilimab injection) versus paclitaxel/irinotecan as second-line therapy for patients with advanced/metastatic ESCC. Tyvyt (sintilimab injection) is an innovative drug jointly developed by Innovent and Eli Lilly and Company in China. Tyvyt (sintilimab injection) is a type of immunoglobulin G4 monoclonal antibody, which binds to the PD-1 molecule on the surface of T-cells, blocks the PD-L1(Programmed Cell Death-1 Ligand-1, PD-L1 pathway)and reactivates T-cells to kill cancer cells. Tyvyt (sintilimab injection) is the only PD-1 antibody in China branded by both a local biopharmaceutical company and a global pharmaceutical company. The ORIENT-15 study is a randomized, double-blind, multi-center, phase III trial that evaluates the efficacy and safety of Tyvyt (sintilimab injection) in combination with chemotherapy as first-line treatment in subjects with unresectable, locally advanced recurrent or metastatic ESCC in China. Patients will receive Tyvyt (sintilimab injection) or placebo in combination with paclitaxel and cisplatin until disease progression. Participants will be randomly assigned in a 1:1 ratio into experimental or control groups. The study will enroll 640 patients. The primary endpoint is overall survival in both the entire population and in PD-L1 positive population of patients.