Sintilimab or Placebo With Chemotherapy in Esophageal Squamous Cell Carcinoma ( ORIENT-15 )

Key Inclusion Criteria:

Histopathologically confirmed unresectable, locally advanced, recurrent or metastatic ESCC (excluding mixed adenosquamous carcinoma and other histological subtypes)
ECOG PS of 0 or 1
Subject must be unsuitable for definitive treatment, such as definitive chemoradiotherapy and/or surgery. For subjects who have received (neo)adjuvant or definitive chemotherapy/radiochemotherapy, time from the completion of last treatment to disease recurrence must be > 6 months Could provide archival or fresh tissues for immunotherapy-drugs-are-boosting-survival/" >PD-L1 expression analysis with obtainable results
Have at least one measurable lesion as per RECIST v1.1

Key exclusion Criteria:

ESCC with endoscopy-confirmed near-complete obstruction requiring interventional therapy
Post stent implantation in the esophagus or trachea with risk of perforation
Received systemic treatment for advanced or metastatic ESCC.
Received a cumulative dose of cisplatin ≥ 300 mg/m2 and the last cisplatin dose was within 12 months of randomization or the first dose of study treatment in the open-label phase.
High risk of hemorrhage or perforations due to tumor invasion in adjacent organs (aorta or trachea), or have fistula formation.
Hepatic metastasis > 50% of the total liver volume.
Received palliative therapy for a local lesion within 2 weeks prior to the first dose.
Received systemic treatment with Chinese traditional medicines with anti-cancer indications or immunomodulators (including thymosins, interferons, and interleukins) within 2 weeks prior to the first dose of study treatment.
Received systemic immunosuppressants within 2 weeks prior to randomization, excluding local use of glucocorticoids administered by nasal, inhaled, or other routes, and systemic glucocorticoids at physiological doses (no more than 10 mg/day of prednisone or equivalents), or glucocorticoids to prevent allergies to contrast media.