How does Retifanlimab exert its anti-cancer effect?

Retifanlimab (Retifanlimab) is an innovative immune checkpoint inhibitor that belongs to the category of programmed death receptor-1 (PD-1) blocking antibodies. It blocks the binding of PD-1 receptor and its ligands PD-L1 and PD-L2, relieves the inhibition of tumor immune escape, and restores the immune system's recognition and attack of tumor cells, thereby exerting a powerful anti-cancer effect. PD-1 is a receptor located on the surface of T cells. Under normal circumstances, it inhibits the activity of T cells by binding to PD-L1 or PD-L2 and prevents the immune system from attacking normal cells.

However, many tumor cells "disguise" themselves by upregulating PD-L1, making it impossible for the immune system to recognize and attack these cancer cells. By blocking this binding, Riflimab enhances the immune response of T cells, allowing the immune system to effectively recognize and destroy tumor cells.

Riflimab has shown significant efficacy in treating certain types of cancer, particularly Merkel cell carcinoma (MCC) and squamous cell carcinoma of the anal canal (SCAC). Merkel cell carcinoma is a rare and highly malignant skin cancer that is often associated with immune evasion mechanisms. Anal canal squamous cell carcinoma is a malignant tumor in the anal area, and immunotherapy has brought new treatment hope. Riflimab, as an immune checkpoint inhibitor, can help the patient's immune system re-recognize these tumor cells, thereby reducing the spread of the tumor and improving the patient's survival rate.

In general, Riflimab restores the function of the immune system and attacks tumor cells by lifting the immunosuppressive effect of PD-1. This mechanism not only applies to Merkel cell carcinoma and anal canal squamous cell carcinoma, but also provides potential therapeutic ideas for other types of cancer immunotherapy. As more clinical data accumulate, reflimab is expected to have a role in a wider range of tumor types.

Reference materials:https://www.drugs.com/mtm/retifanlimab.html