Organic Synthesis for Immune Checkpoint Targeted Small Molecule Inhibitor

The immune checkpoint system has been recognized as a promising therapeutic target in cancer treatment. Immune checkpoint molecules can protect tissues from the damage caused by the immune system during pathogenic infections. Although cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death 1/programmed cell death 1 ligand (PD-1/PD-L1) are the two furthest-studied immune checkpoints, many other checkpoints are currently being investigated for their potentials to improve anti-tumor immunity. Recently, the small-molecule inhibitor has been identified as an attractive combination partner for immune checkpoint inhibitors and is gradually becoming an important direction for combination drug design. With ample experience in drug development and immune checkpoint research, Creative Biolabs provides a full range of high-quality small molecule drug design services, including organic synthesis for immune checkpoint targeted small molecule inhibitors.

PD‑1/PD‑L1 inhibitors. Fig.1 PD‑1/PD‑L1 inhibitors. (Sasikumar, 2018)

Organic Synthesis for Drug Design

Modern drug discovery often involves screening small molecules for their ability to bind to a preselected protein target. Drug discovery can also include screening small molecules for their ability to modulate a biological pathway in cells or organisms. One goal of organic syntheses is to efficiently synthesize a collection of small molecules capable of perturbing any disease-related biological pathway, leading eventually to the identification of therapeutic immune checkpoint targets.

  • Target-Oriented Synthesis and Retrosynthetic Analysis
  • A systematic method to plan syntheses of target molecules, named retrosynthetic analysis, can be used to start with a structurally complex target and find a structurally simple compound that can be used to start synthesis. Retrosynthetic analysis is the sine qua non of target-oriented synthesis and has been used in the synthetic planning of many target compounds of value in medicine and biology. Creative Biolabs offers target-oriented synthesis and retrosynthetic analysis to meet every particular requirement of our global customers.

Fig. 1 Organic Synthesis for Immune Checkpoint Targeted Small Molecule Inhibitor. (

  • Solid Phase Synthesis
  • Solid-phase peptide synthesis can be used to overcome the technical challenge of performing many couplings to yield long chains. The nascent polypeptide chain is immobilized in this method, most commonly to spherical polystyrene beads, allowing coupling reagents to be added in high molar excess and by-products to be removed simply by washing the insoluble beads. Creative Biolabs offers solid-phase peptide synthesis for nonpeptidic small molecules to meet your drug development goal in a time-saving manner.

  • Diversity-Oriented Synthesis
  • From the perspective of drug discovery, the diversity-oriented synthesis approach offers the means for the simultaneous identification of proteins that can serve as targets for therapeutic intervention and small molecules that can modulate the functions of these therapeutic targets. Creative Biolabs possesses enriched experience in immune checkpoint targeted small molecule development and could offer diversity-oriented synthesis services for a fully customized drug development process.

Creative Biolabs provides organic synthesis for immune checkpoint targeted small molecule inhibitors. We can design and synthesize a broad spectrum of compounds for multiple receptor targets. With years of experience in drug discovery and organic synthesis, our specialists in synthesis focus on developing the small-molecule inhibitors and activators of the immune checkpoint receptors. If the above services do not meet your requirements, please contact us for your exclusive solution.


  1. Sasikumar, P.G.; Ramachandra, M. Small-molecule immune checkpoint inhibitors targeting PD-1/PD-L1 and other emerging checkpoint pathways. BioDrugs. 2018, 32, 481-497.

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