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Biologic
RCSB PDB 5DK3

Pembrolizumab

Keytruda
Mechanism of action
PD-1 ()
In plain language
A lab-made that attaches to the PD-1 protein on immune cells, blocking a signal cancer cells use to hide, so the immune system can recognize and attack the tumor.
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How it works
Pembrolizumab is a humanized IgG4 monoclonal antibody that binds with high specificity to the PD-1 on T cells. This binding blocks PD-1 from interacting with its , PD-L1 and PD-L2, which tumor cells often exploit to suppress T-cell activity. By interrupting this checkpoint interaction, pembrolizumab restores T-cell proliferation and cytotoxic function that had been dampened within the tumor microenvironment. The result is renewed immune-mediated recognition and destruction of cancer cells, rather than any direct cytotoxic action on the tumor itself.
Therapeutic applications
Pembrolizumab carries FDA approvals across a broad range of malignancies, reflecting its role as a pan-tumor checkpoint inhibitor. Representative major indications include melanoma (unresectable/metastatic and adjuvant), non-small cell lung cancer, classical Hodgkin lymphoma, urothelial (bladder) cancer, head and neck squamous cell carcinoma, and MSI-H/dMMR or TMB-H solid tumors including colorectal cancer, in addition to numerous other tumor types such as gastric, cervical, hepatocellular, renal cell, and endometrial cancers.
Class
Monoclonal antibody
Therapeutic area
Immuno-oncology
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