this study is a non-randomized, phase II, open-label study. Phase II clinical trials test the safety and effectiveness of an investigational drug or combination of drugs to learn whether it works in preventing or treating a disease.~the purpose of this study is to evaluate the effectiveness of sintilimab in preventing the onset of oral cancer in patients with high-risk oral premalignant lesions, who had oral cancer at least once before.
This is a non-randomized, phase II, open-label study. The goal of this clinical research study is to investigate how well sintilimab works in preventing high-risk oral premalignant lesions cancerization.