TREATMENT OF CD47+ DISEASE CELLS WITH SIRP ALPHA-FC FUSIONS

摘要

CD47+ disease cells, such as CD47+ cancer cells, are treated with an agent that blocks signalling via the SIRPa/CD47 axis. The agent is a human SIRPa fusion protein that displays negligible CD47 agonism and negligible red blood cell binding. The fusion protein comprises an IgV domain from variant 2 of human SIRPa, and an Fc having effector function. The IgV domain binds human CD47 with an affinity that is at least five fold greater than the affinity of the entire extracellular region of human SIRPa. The fusion protein is at least 5 fold more potent than a counterpart lacking effector function.