1396 TriTCE CPI: a novel trispecifc T cell engager platform with integrated PD-1/PD-L1 checkpoint inhibition engineered for the treatment of immunosuppressed tumors by Matteo Zago, Yun Peng, Meghan M Verstraete, Maya Poffenberger, Veronica Luu, Brenda Ma, Nichole Escalante, Janessa Li, Diego Perez Escanda, Siran Cao, Edward Meier, Sifa Arrafi, Anna Von Rossum, Genevieve Desjardins, Nina Weisser, Thomas Spreter von Kreudenstein