[P4–155]: DERIVING A CUT‐OFF FOR THE ELECSYS® β‐AMYLOID (1–42) IMMUNOASSAY FOR USE IN CLINICAL TRIALS SUPPORTED BY ELI LILLY FOR PATIENTS WITH CLINICALLY DEFINED ALZHEIMER's DISEASE (AD). (1st July 2017) - Shaw, Leslie M.; Waligorska, Teresa; Fields, Leona; Korecka, Magdalena; Figurski, Michal J.; Trojanowski, John Q.; Eichenlaub, Udo; Wahl, Simone; Quan, Marian; Lachno, David Richard; Talbot, Jayne A.; Andersen, Scott W.; et al.