PHASE 1:

Background • Tumors attempt to evade the immune system by upregulating CD47, a marker of self. By blocking CD47 interaction with its myeloid cell receptor SIRPα, it may be possible to enhance innate and adaptive immunity against cancer.1 • ALX148 is a fusion protein comprised of an engineered high affinity CD47 binding domain of SIRPα genetically linked to an inactive Fc region of human immunoglobulin (Figure 1).2, 3 • In non clinical models, ALX148 blocks CD47 and safely enhances the activity of several anti-cancer targeted antibodies and checkpoint inhibitors through Fc dependent and independent mechanisms, bridging innate and adaptive anti-cancer immune response.2,3 • Based upon these observations, AT148001, a first-in-human phase 1 study of ALX148 administered as a single agent (Part 1) and in combination with established anticancer antibodies (Part 2) was initiated.