Survival Of Chemotherapy (Chemo) Refractory Gastric Or Gastroesophageal Junction Cancer (Gc/Gejc) Patients From Flatiron Health (Fh): Matched Clinical Characteristics To Attraction-2 And Checkmate-032.

51Background: Treatments for advanced/metastatic (adv/met) GC/GEJC after failure of second-line (2L) chemo are limited. Nivolumab (NIVO) demonstrated encouraging anti-tumor activity and long-term OS in adv/met GC/GEJC Asian patients (pts) in ATTRACTION-2 compared with placebo (12-month OS rate, 26% vs 11%; HR, 0.63; P u003c .0001) and in CHECKMATE-032 (CM-032) in Western pts (12-months OS rate, 45%). This study explored outcomes in US GC/GEJC pts by establishing real world (RW) standard of care (SOC) comparators, against placebo in Asian pts and NIVO in Western pts. Methods: Data were captured from FH electronic health record database. Median OS, estimated by Kaplan-Meier, was calculated from last treatment for adv/met GC/GEJC to death. To create a US RW SOC arm to the ATTRACTION-2 placebo pts, a 2-step matching process was applied: (1) similar inclusion/exclusion (I/E) criteria (2) frequency matching based on significant differences in baseline characteristics associated with survival, identified by univaria...