What is pembrolizumab's target?
Pembrolizumab (Keytruda) targets PD-1, or programmed cell death protein 1, a receptor on T cells that inhibits immune responses.
What ligand binds to PD-1?
PD-1's primary ligand is PD-L1 (programmed death-ligand 1), also called B7-H1. It binds PD-1 with high affinity, triggering immune suppression to prevent overactive responses. PD-L2 (B7-DC) is a secondary ligand with lower affinity.
How does pembrolizumab block this interaction?
Pembrolizumab is a monoclonal antibody that binds directly to PD-1, preventing PD-L1 or PD-L2 from attaching and restoring T-cell activity against tumors.
Why does this matter for cancer treatment?
Tumors often overexpress PD-L1 to evade immunity. Blocking PD-1/PD-L1 revives anti-tumor responses, as shown in approvals for melanoma, lung cancer, and others.
Related targets and drugs
Nivolumab also targets PD-1; PD-L1 inhibitors like atezolizumab bind the ligand instead. No patents listed on DrugPatentWatch.com for pembrolizumab's PD-1 binding domain specifically, but formulation patents extend to 2028 in some regions.[1]
[1] DrugPatentWatch.com - Pembrolizumab patents