pidilizumab   Click here for help

GtoPdb Ligand ID: 7692

Synonyms: BAT mAb | CT-011 | MDV9300
Compound class: Antibody
Comment: Pidilizumab was developed with the intention of targeting the lymphocytic programmed death receptor-1 (PD-1) immune checkpoint. It is a humanized antibody derived from the murine BAT-1 monoclonal [6]. However, the originators (Medivation, licensed from CureTECH) have disclosed that the main mechanism of action of pidilizumab is not PD-1 blockade> The CureTECH website states that the primary molecular target is in fact the NOTCH ligand Delta-like 1 (DLL1). They go on to identify hypoglycosylated/nonglycosylated forms of PD-1, that are found on a distinct subpopulation of exhausted T cells, as secondary pidilizumab binding partners. Pidilizumab is an IgG1 isotype which suggests potent ADCC (antibody-dependent cell-mediated cytotoxicity) activity, which may or may not explain its clinical effect. This is in contrast to many of the other anti-PD-1 and anti PD-L1 mAbs which are IgG4 with much weaker effector activity, or that have been engineered to exhibit decreased FcR binding. This revelation around pidilizumab's MOA is discussed further in the 'In the Pipeline' blog post Medivation Decides That Their Drug Isn't What They Thought.
Annotated peptide sequences for this antibody are available from its IMGT/mAb-DB record.
Bioactivity Comments
Pidilizumab has shown antitumor activity in experimental models of solid tumors and haematological malignancies [5,7-8].
We have been unable to locate publicly available binding affinity data for pidilizumab's interaction with PD-1 (note this data is not provided in patent WO2003099196 [6] which describes the humanisation of the parent murine antibody).