370 Pharmacodynamic assessment of a novel FAP-targeted 4–1BB agonist, administered as single agent and in combination with atezolizumab to patients with advanced solid tumors oleh Josep Tabernero, Maurizio Ceppi, Victor Moreno, Michael Hettich, Miguel Sanmamed, Christina Claus, Tatiana Hernandez, Iben Spanggaard, Analia Azaro, Maria Martinez Garcia, Alejo Rodriguez-Vida, Florian Heil, Oliver Krieter, Oliver Grimm, Marta Canamero, Jose Duarte, Alexandra-Cristina Nica, Iakov Davydov, Chia-Huey Ooi, Christian Heichinger, Ernesto Guarin, Radoiane Helbaj, Tamara Tanos, Eveline Nueesch, Irene Moreno