APL-502: Anti Programmed Death Ligand-1
APL-502 is a novel IgG1 humanized monoclonal antibody against the Programmed Death Ligand-1 (PD-L1) membrane receptor. APL-502 shows significant sequence divergence in complementarity-determining regions (CDRs) from other anti- PD-L1 antibodies in the market today. Pre-clinical pharmacodynamics and toxicology studies of APL-502 demonstrated pharmacological activity and the agent is well tolerated at effective doses with a wide margin of safety. In vitro studies have demonstrated binding affinity while in-vivo efficacy and safety data in the murine models compared favorably to atezolizumab.
PD‑1 protein is expressed on immune cells called T cells normally acting as a type of "off switch" that helps keep the T cells from attacking other cells in the body (e.g. healthy cells). PD‑L1 protein is expressed on some normal cells and on cancer cells. PD-1 binds to PD‑L1 and this interaction signals T cells to leave the other cell alone and not attack it. This protects normal, healthy cells from immune attack. But, some cancer cells hijack PD‑L1 expression so the PD-1 expressing T cell adopts a “don’t attack” state which helps the cancer cells hide from the immune system and subsequently grow. Therapies that target PD-1 stop it from interacting with PD-L1. Similarly, therapies that target PD-L1 prevent PD-1 from interacting with it. This allows the T cell to attack cancer cells in the body and prevent them from hiding.
Apollomics retains worldwide rights to APL-502 outside of China.