Tislelizumab is a monoclonal antibody designed to target the PD-1 receptor on T cells. It works by blocking the interaction between PD-1 and its ligands PD-L1 and PD-L2, thereby restoring the immune system’s ability to detect and attack cancer cells. This mechanism makes it a key agent in cancer immunotherapy.

It is primarily used in the treatment of various advanced or metastatic cancers, including classical Hodgkin lymphoma, urothelial carcinoma, non-small cell lung cancer, and esophageal squamous cell carcinoma. Clinical studies have shown improved response rates and prolonged survival in patients, especially those who have progressed after prior therapies.

Tislelizumab is administered intravenously and is often used as a monotherapy or in combination with chemotherapy, depending on the cancer type and stage. Its use is supported by biomarker testing, such as PD-L1 expression levels, to identify patients most likely to benefit.

Ongoing research explores its efficacy in additional tumor types and in earlier lines of treatment, including neoadjuvant and adjuvant settings. Due to its targeted action, it generally has a manageable safety profile, though immune-related adverse events such as pneumonitis, colitis, and hepatitis require careful monitoring.