 In a Phase I study across nine tumor types, Agenus Incs NASDAQ: AGEN CTLA-4 drug AGN1181 posted one complete response and three partial responses PRs as a monotherapy, according to data presented t SITC. The three responders expressed the low-affinity FcγRIIIA receptor, Agenus said, which is associated with a lack of response to first-generation CTLA-4 inhibitors. 