VIKTORY trial: Report on AZD1775/paclitaxel in TP53 mutation (+) GC, selumetinib/paclitaxel in ras aberrant GC, AZD5363/paclitaxel in PIK3CA mt and biomarker negative, savolitinib/docetaxel in met (+), and vistusertib/paclitaxel in RICTOR(+) GC.

4024 Background: The VIKTORY trial is a biomarker-based umbrella trial in GC. Methods: See table below. Results: From June 2014 to Jan 2017, 432 metastatic gastric cancer patients were enrolled. 124 (28.7%) were treated on one of the associated study protocols. At January 2017, 25 pts were allocated to selumetinib/paclitaxel arm, 25 to AZD1775/paclitaxel arm, 16 to AZD5363/paclitaxel arm, 16 to vistusertib/paclitaxel arm, 4 to savolitinib monotherapy, 19 to savolitinib/docetaxel arm, 19 to phase I AZD6738/paclitaxel arm. Initial efficacy signals have been seen in several arms (selumetinib/paclitaxel, 6 of 21 evaluable patients in PR). Correlative analyses between molecular signatures and treatment response are ongoing and will be presented at the meeting. For vistusertib/paclitaxel in the biomarker negative arm, we found RICTOR amplification as a promising predictive biomarker for response. Two (of three) GC patients with RICTOR amplification achieved PR to vistusertib/paclitaxel. Conclusions: This is one of the first attempts to undertake a biomarker-driven trial in metastatic GC. 28.7% of the patients were guided to one of the parallel arms based on molecular screening outcomes. We were able to identify potential molecular targets in the biomarker-negative arm, for further assessment in new protocols. Clinical trial information: 02299648. [Table: see text]