QL1706 Plus Celecoxib in Advanced Esophageal Squamous Cell Carcinoma

QL1706 (anti-PD-1/CTLA-4 bispecific antibody) will be administered at 5 mg/kg by intravenous infusion every 3 weeks. Celecoxib 200 mg will be taken orally twice daily starting on Day 1 of each 3-week treatment cycle. Treatment continues until disease progression, intolerable toxicity, or for a maximum of 2 years.