Immune checkpoint inhibiting immunotherapies are the class of monoclonal antibody therapies that prevents T-cell inhibition and promotes the activation and proliferation of effector T cells. Two such receptors CTLA-4 & PD-1 that are expressed in T cells transduce inhibitory signals after binding to its ligand. The monoclonal antibodies targeted against these receptors or their ligands have been shown to increase the tumor-killing activity of T cells.
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| Figure: Immune Check Point Inhibiting Monoclonal Antibodies and its Target in T cells and Tumors. Pembrolizumab (Keytruda), Nivolumab (Opdivo), Cemiplimab (Libtayo) blocks PD-1 expressed in T cells. Atezolizumab (Tecentriq), Avelumab (Bavencio), Durvalumab (Imfinzi) blocks PD-L1 expressed in tumor cells. Ipilimumab (Yervoy) blocks CTLA-4 antigen present in T cells |
PD-1 inhibiting antibodies:
These monoclonal antibodies block the PD-1 signaling by binding to its ligand PD-1 expressed in the T cells. Examples include
PD-L1 inhibiting antibodies:
These monoclonal antibodies block the inhibitory PD-1 signaling by binding to its ligand PD-L1 expressed in the tumor cells. Examples include
CTLA-4 Inhibiting antibodies:
These monoclonal antibodies block the inhibitory CTLA-4 signaling by binding to CTLA-4 expressed in the tumor cells. Example include
Indications of Immune Check Point Inhibiting Antibody Therapies
Immune checkpoint inhibiting antibody therapies have shown promise in treatment of
- Melanoma,
- Small Non-Cell Lung Cancer,
- Urothelial Carcinoma,
- Renal Cell Carcinoma etc.
Refer to prescribing information for the indication of each drug.