PD-1 Immune Checkpoint Molecule for Drug Development

introduction to PD-1

Programmed cell death protein 1 (PD-1), also known as cluster of differentiation 279 (CD279), belongs to the CD28 superfamily and is a cell surface protein that plays a critical role in mediating immune responses of T cells and pro-B cells. PD-1 is usually expressed on various T cells. Its ligands (PD-L1 or PD-L2) are often found in dendritic cells (DCs) or macrophages. The binding of PD-1 to its ligands can trigger the T cells' activation and tolerance in different types of diseases, such as autoimmune diseases and cancers. Moreover, pilot studies have revealed that the PD-1 can be treated as key immune checkpoint molecules and exerts a broader range of immune-regulatory roles in disease development. For instance, many studies have illustrated that the interaction between PD-1 and PD-L1/PD-L2 can protect the human body from diseases by killing pathogens or harmful cells. Therefore, PD-1 and its ligand have been considered as a new therapeutic strategy for disease immunotherapy.

Inhibition of PD-1 and its ligand PD-L1. Fig.1 Inhibition of PD-1 and its ligand PD-L1. (Li, 2019)

Immune Checkpoint PD-1 for Drug Development

In the past few years, immune checkpoints have shown a promising role in treating various diseases, including cancers. The immune checkpoint drugs are usually designed by blocking or inhibiting the signal pathways of T cells or B cells, thus achieving resistance to diseases. A wide variety of immune checkpoint molecules, such as PD-1/PD-L1, are potential immune targets for the body's immune regulation. Novel drugs targeting the PD-1/PD-L1 pathway have been widely developed.

Many attempts have been made recently to discover inhibitors targeting PD-1/PD-L1 for treating different kinds of tumors, including but not limited to advanced melanoma and non-small cell lung cancer (NSCLC). The clinical data have shown that these antibodies targeting PD-1 and its ligand PD-L1 can block the activation of T cells and induce anti-tumor activities to improve patients' outcomes in the clinic. Nowadays, several small-molecules PD-1/PD-L1 drug-like inhibitors have been developed for the treatment of many cancers.

Services at Creative Biolabs

Creative Biolabs is a well-recognized expert who supports a broad range of drug development projects for immune checkpoints. Currently, a series of custom services for immune checkpoint PD-1 is available at Creative Biolabs, including but not limited to:

Please do not hesitate to contact us for more detailed information.


  1. Li, K.; et al. Development of small-molecule immune checkpoint inhibitors of PD-1/PD-L1 as a new therapeutic strategy for tumor immunotherapy. Journal of drug targeting. 2019, 27(3): 244-256.

All listed customized services & products are for research use only, not intended for pharmaceutical, diagnostic, therapeutic, or any in vivo human use.