IGF2 Peptide-Based LYTACs for Targeted Degradation of Extracellular and Transmembrane Proteins.

Lysosome-targeting chimeras (LYTACs) have recently been developed to facilitate the lysosomal degradation of specific extracellular and transmembrane molecular targets. However, the LYTAC particles described to date are based on glycopeptide conjugates, which are difficult to prepare and produce on a large scale. Here, we report on the development of pure protein LYTACs based on the non-glycosylated IGF2 peptides, which can be readily produced in virtually any facility capable of monoclonal antibody production. These chimeras utilize the IGF2R/CI-M6PR pathway for lysosomal shuttling and, in our illustrative example, target programmed death ligand 1 (PD-L1), eliciting physiological effects analogous to immune checkpoint blockade. Results from in vitro assays significantly exceed the effects of anti-PD-L1 antibodies alone.

Development of the Inhibitors that Target the PD-1/PD-L1 Interaction-A Brief Look at Progress on Small Molecules, Peptides and Macrocycles.

Cancer immunotherapy based on antibodies targeting the immune checkpoint PD-1/PD-L1 pathway has seen unprecedented clinical responses and constitutes the new paradigm in cancer therapy. The antibody-based immunotherapies have several limitations such as high production cost of the antibodies or their long half-life. Small-molecule inhibitors of the PD-1/PD-L1 interaction have been highly anticipated as a promising alternative or complementary therapeutic to the monoclonal antibodies (mAbs). Currently, the field of developing anti-PD-1/PD-L1 small-molecule inhibitors is intensively explored. In this paper, we review anti-PD-1/PD-L1 small-molecule and peptide-based inhibitors and discuss recent structural and preclinical/clinical aspects of their development. Discovery of the therapeutics based on small-molecule inhibitors of the PD-1/PD-L1 interaction represents a promising but challenging perspective in cancer treatment.