LBA8035 Background: IMpower010 (NCT02486718) met its primary endpoint of significant DFS improvement with atezo vs BSC after adj chemotherapy in resected NSCLC in the PD-L1 TC ≥1% and all-randomized stage II-IIIA populations, leading to worldwide approval of adj atezo for PD-L1 TC ≥1% or PD-L1 TC ≥50% stage II-IIIA NSCLC. At OS IA1, a trend favoring atezo was seen in the PD-L1 TC ≥1% stage II-IIIA population. Here we report findings from the DFS FA and OS IA2. Methods: The IMpower010 study design has been previously described (Felip et al, Lancet 2021). The primary DFS and secondary OS endpoints were tested hierarchically: DFS in the PD-L1 TC ≥1% (SP263) stage II-IIIA, then in the all-randomized stage II-IIIA, and then in the intent-to-treat (ITT; stage IB-IIIA) populations, followed by OS in the ITT population. Secondary endpoints included 3- and 5-y DFS and DFS in the PD-L1 TC ≥50% (SP263) stage II-IIIA population. OS in the ITT population could only be formally tested if the significance boundary for DFS in that population was crossed. Results: At the DFS FA and OS IA2 (clinical cutoff date: Jan 26, 2024), with a minimum follow-up of 60 mo, DFS and OS for the PD-L1 TC ≥1% and TC ≥50% stage II-IIIA populations were consistent with previously observed benefit; the difference in median (m) DFS between arms in the PD-L1 TC ≥1% population was 31.2 mo (Table). In the ITT population, the significance boundary for DFS was not crossed and OS was similar between arms, although data were immature. The safety profile of atezo was consistent with prior analyses. Conclusions: These results provide the first cancer immunotherapy data with ≥5 y of follow-up from a Phase III study in resectable NSCLC. Although the statistical boundary for the ITT population was not crossed, DFS benefit with adj atezo continues to translate into a positive OS trend vs BSC in the PD-L1 TC ≥1% and TC ≥50% stage II-IIIA populations. These results further support the use of adj atezo in PD-L1–selected populations. Clinical trial information: NCT02486718 . [Table: see text]

IMpower010: Final disease-free survival (DFS) and second overall survival (OS) interim results after ≥5 years of follow up of a phase III study of adjuvant atezolizumab vs best supportive care in resected stage IB-IIIA non-small cell lung cancer (NSCLC).