1307P Blood-based genomic profiling of advanced non-small cell lung cancer (aNSCLC) patients (pts) from blood first assay screening trial (BFAST) and comparison with real-world data (RWD)

BFAST (NCT03178552) is an ongoing global study evaluating the relationship between blood-based next-generation sequencing (NGS) detection of actionable genetic alterations in circulating tumour DNA and activity of targeted therapies and immunotherapy in pts with 1L aNSCLC. The natural history Cohort Z is non-interventional and collects RWD for pts not receiving treatment as part of the trial. We present BFAST screened pts’ characteristics and prevalence of genomic alterations detected in blood. BFAST pts were screened using Foundation Medicine, Inc. (FMI)’s liquid biopsy assay (FoundationACT). Demographics and genomic alteration prevalence of 5847 BFAST screened pts (as of 31 Dec 2019) were compared with a concurrent cohort of 3784 aNSCLC pts from the de-identified Flatiron Health-FMI Clinico-Genomic Database (CGDB) of FMI-tested US pts who were treated in the Flatiron Health network. ∼80% of these pts were tissue-tested, including 1293 “BFAST-like” pts who were tested before 1L treatment and were ECOG PS 0–2 at testing. The prevalence of genomic alterations was similar in BFAST-screened and concurrent CGDB pts, with the exception of KRAS and PIK3CA alterations, which were higher in CGDB pts (Table). BFAST pts were younger (median age 66 vs 70 yrs) with a higher proportion of Asian (20 vs 4%), male (59 vs 50%) and ECOG PS 0–1 pts (91 vs 67%), and fewer smokers (69 vs 83%). To our knowledge, BFAST is the first blood-based NGS genomic survey of a large cohort of 1L aNSCLC pts in a global clinical trial setting. The prevalence of genomic alterations was generally similar to CGDB, despite the use of blood assays vs predominantly tissue assays. Future comparisons of BFAST Cohort Z, CGDB tissue- and blood-tested pts, and their clinical outcome, will provide insights into the value of blood-based NGS testing in global trial and community settingsTable: 1307PPrevalence of select genomic alterations, n (%)BFAST screened (n=5847)BFAST-like CGDB* (n=1293)CGDB (n=3784)EGFR+889 (15)186 (14)624 (16)L858R258 (4)52 (4)178 (5)Exon 19 deletion364 (6)64 (5)240 (6)Exon 20 insertion81 (1)13 (1)37 (1)KRAS+1211 (21)419 (32)1069 (28)G12C428 (7)163 (13)375 (10)ALK fusion194 (3)21 (2)94 (2)ROS1 fusion47 (0.8)6 (0.5)23 (0.6)RET fusion71 (1)7 (0.5)29 (0.8)BRAF V60062 (1)23 (2)61 (2)MET exon 14 skipping86 (1)21 (2)64 (2)PIK3CA+334 (6)120 (9)365 (10)*ECOG PS 0–2, tested before 1L treatment. Open table in a new tab .