PYX-106 is a fully human monoclonal antibody designed to target Siglec-15, an immune suppressor that is broadly expressed across different tumor types as well as macrophages. Since Siglec-15 and PD-L1 have limited overlap, PYX-106 could address PD-1/PD-L1 non-responders across a variety of tumor types and may be integral in combination with other immunotherapies.
PYX-106 demonstrated a significantly longer half-life of seven days in an exploratory non-human primate study and a six-fold greater binding affinity to Siglec-15 compared to current benchmarks, which could allow for less frequent dosing while maintaining optimal activity.