Liquid biopsy (LB) is an important alternative for advanced lung cancer patients in diagnosing resistance or where tissue genotyping has failed. The VALUE study examines clinical outcomes and utility of LB for molecular diagnosis in treatment naive stage IV lung adenocarcinoma patients. [Preliminary data previously presented at ASCO2020. Final study results will be available for WCLC2021] This study is being conducted at 6 Canadian centres (NCT03576937) using Guardant360TM (G360), a validated cell-free DNA next-generation sequencing assay that identifies variants in 74 cancer-associated genes, including fusions and copy number gain. Patients with treatment-naïve advanced non-squamous lung carcinoma, ≤10 pack-year smoking history, and measurable disease are eligible (N=150). Patients receive standard of care tumour tissue (TT) molecular profiling (EGFR, ALK +/- ROS1) and LB. The primary endpoint is response rate to first-line therapy (RECIST 1.1); secondary endpoints include incremental targetable alterations identified through G360 (EGFR, ALK, BRAF, ERBB2, KRAS (G12C), NTRK, MET (amplification, exon 14 skipping), RET, ROS1), turnaround time (TAT) and successful molecular profiling rates. To date, 150 eligible patients have been enrolled. Demographic data are available for the first 100 patients, treatment data for 89 and 60 have response data. Median age is 63 (range 22-91), 63% are female, 85% never smokers, 35% East Asian, 24% ECOG PS>1, and 94% have adenocarcinoma. Actionable targets have been identified in 55% of patients using G360 (EGFR/ALK in 38%), and 38% using standard TT profiling. Concordance between TT and LB was high, 84%, with 8 cases each identified by TT or LB but not the other. TT profiling for EGFR/ALK was unsuccessful in 6% of patients (insufficient tissue, failed biopsy, single biomarker tested only). Fifteen patients (15%) had no ctDNA alterations detected by G360 (low disease burden vs. non-shedding). Of 89 patients receiving first-line treatment, 60% received targeted therapy, 26% chemo-immunotherapy combinations, 10% checkpoint inhibitors alone and 4% were observed. Treatment decisions were informed by G360 alone in 40% and by G360+TT results in 28% (by physician report). Among 51 evaluable patients, ORR was 55% (28/51). Using G360, ORR was 75% (18/24) in those with actionable alterations and 37% (10/27) in those without. Using TT, ORR was 64% (16/25) in those with actionable alterations and 46% (12/26) in those without. Mean TAT was 7.7 days (SD+/-1.6) for LB vs 20.8 days (SD+/- 9.8) for TT. LB using G360 identifies actionable targets beyond tissue profiling alone in newly diagnosed lung cancer patients, has faster TAT and yields similar outcomes with targeted and non-targeted therapy.