Tislelizumab (brand name Tevimbra) is a humanized IgG4 monoclonal antibody targeting PD‑1, used as an immune checkpoint inhibitor in several solid tumors.
It enhances T‑cell–mediated anti‑tumor activity by blocking interaction of PD‑1 with its ligands PD‑L1 and PD‑L2.
Tislelizumab binds the extracellular domain of PD‑1 on T cells, preventing ligand-induced inhibitory signaling and restoring T‑cell proliferation and cytokine production against tumor cells.
Its Fc region is engineered to minimize binding to Fcγ receptors on macrophages, which is intended to reduce antibody‑dependent phagocytosis of PD‑1–positive T cells and thus limit a potential resistance mechanism seen with some other PD‑1 antibodies.
Major labeled uses include: Esophageal squamous cell carcinoma (ESCC): as monotherapy after prior systemic chemotherapy and, more recently, in combination with platinum‑based chemotherapy as first‑line therapy in unresectable or metastatic PD‑L1–positive ESCC.
Gastric and gastroesophageal junction (GEJ) adenocarcinoma: in combination with platinum‑ and fluoropyrimidine‑based chemotherapy as first‑line treatment for unresectable or metastatic HER2‑negative disease with PD‑L1 expression in adults.
Non‑small cell lung cancer (NSCLC) and extensive‑stage small‑cell lung cancer (ES‑SCLC): including monotherapy after platinum in NSCLC and in combination with platinum‑based chemotherapy for certain first‑line NSCLC and ES‑SCLC indications.
The recommended dose in current labels is 200 mg IV every 3 weeks, typically as a fixed‑dose infusion over a set period, alone or combined with platinum‑based chemotherapy depending on indication.
In the phase III RATIONALE‑302 trial in previously treated advanced ESCC, tislelizumab improved median overall survival to about 8.6 months versus 6.3 months with investigator’s choice chemotherapy, leading to regulatory approval.
Additional phase III trials, such as RATIONALE‑306 in first‑line ESCC and trials in gastric/GEJ cancer, have shown survival and response benefits when tislelizumab is combined with platinum‑based regimens, supporting its expanded indications.
The toxicity profile is consistent with other PD‑1 inhibitors, with mostly mild to moderate adverse events and a recognizable spectrum of immune‑related events.
Common issues include fatigue, rash, pruritus, diarrhea, and endocrinopathies, and more serious but less frequent events include pneumonitis, hepatitis, colitis, nephritis, and severe infusion reactions, all managed by established immunotherapy algorithms of hold/discontinue plus corticosteroids as appropriate.