80O Atezolizumab (atezo) vs best supportive care (BSC) in stage II-IIIA NSCLC with high PD-L1 expression: Sub-analysis from the pivotal phase III IMpower010 study

IMpower010 showed significant DFS benefit with atezo after adjuvant chemo in resected NSCLC (Felip Lancet 2021). At the interim analysis, significance boundary was crossed for stage II-IIIA PD-L1 TC ≥1% population (stratified HR, 0.66; 95% CI: 0.50, 0.88), greatest ≥50% subgroup (unstratified 0.43; 0.27, 0.68). Here we present further analyses pts. (NCT02486718) study design and primary analysis details have been reported (VENTANA SP263 assay) (UICC/AJCC v7) pts a prespecified secondary endpoint; additional data are exploratory. Baseline characteristics were generally balanced atezo- vs BSC-arm (male, 77% 68%; III, 46% 50%; nonsquamous, 59% 61%). Median follow-up 34.2 mo (21 Jan 2021 cutoff). See table data. Safety consistent that of overall known safety profile atezo. Initial disease relapse this locoregional-only 15/25 atezo-arm (60%) 17/50 (34%) distant-only 6/25 (24%) 21/50 (42%); initial CNS-only seen 1/25 (4%) 7/50 (14%). 19 relapsing (76%) 30 had subsequent systemic therapy (mostly chemo, 60% 32%; immunotherapy, 16% 38%). derived BSC at analysis. Data across most subgroups, albeit limited pt numbers post hoc Numerically, more distant CNS relapses BSC. The tolerability line population, demonstrating positive benefit-risk profile.Table: 80OInterim DFS: II-IIIAPts, nUnstratified HR (95% CI)AtezoBSCAge <65 y ≥65 y71 4470 440.49 (0.27, 0.89) 0.36 (0.17, 0.75)Sex Male Female89 2678 360.50 (0.28, 0.34 (0.15, 0.76)Histology Squamous Nonsquamous47 6845 690.60 (0.29, 1.26) (0.20, 0.65)Stage II IIIA62 5357 570.51 (0.26, 1.00) 0.38 0.72)Regional LN N0 N1 N230 43 4221 52 411.09 (0.39, 3.07) 0.29 (0.12, 0.72) 0.35 (0.18, 0.68)Smoking status Current/former Never99 1699 150.40 (0.24, 0.68) 0.46 1.25)EGFR/ALK mutation Detected Undetected Unknown9 5411 54 490.26 (0.06, 1.02) 0.41 0.84) 0.45 (0.23, 0.91)DFS event/pts: atezo, 28/115 (24%); BSC, 52/114 (46%). Open new tab