Five-year outcomes with first-line (1L) nivolumab + ipilimumab + chemotherapy (N + I + C) vs C in patients (pts) with metastatic NSCLC (mNSCLC) in CheckMate 9LA.

8560 Background: InCheckMate 9LA (NCT03215706), 1L N + I + C demonstrated long-term, durable survival benefit vs C alone in pts with mNSCLC, regardless of tumor PD-L1 expression or histology. Here, we report updated efficacy and safety data with a 5-y follow up (f/u) and outcomes in 5-y survivors. Methods: Adults with stage IV or recurrent NSCLC, ECOG PS ≤ 1, and EGFR/ALK wild-type were randomized 1:1 to N 360 mg Q3W + I 1 mg/kg Q6W + C Q3W (2 cycles; n = 361) or C alone Q3W (4 cycles; n = 358). Maintenance pemetrexed was allowed for pts with non-squamous (NSQ) NSCLC (C arm only). Assessments were OS, PFS, ORR, DOR, treatment (tx)-free interval (TFI; time from last study tx dose to start of subsequent systemic tx or death), and safety. Exploratory analyses included quantifying the number of ipilimumab doses received by 5-y survivors, as well as PFS and TFI in these pts. Results: With a median f/u of 64.5 mo (database lock, 15 Dec 2023), clinical benefit continued to be seen with N + I + C vs C in all randomized pts (Table); 5-y OS rates were 18% vs 11%, respectively. Of pts treated with N + I + C, 11% were tx-free at 5 y. Clinical outcomes favored N + I + C vs C across tumor PD-L1 expression and histology subgroups (Table). In pts with tumor PD-L1 < 1%, 5-y OS and PFS rates with N + I + C were both ~3-fold higher than with C, and 5-y DOR rates were 25% vs 0% in the respective tx arms. Among pts who discontinued N + I + C due to tx-related adverse events (TRAEs; n = 61), 37% were alive at 5 y, and the TFI rate was 22%. In analyses of 5-y survivors, PFS favored N + I + C (n = 48) vs C (n = 30; HR, 0.52 [95% CI, 0.26–1.02]), and 5-y TFI rates were 72% vs 35%, respectively. Of 5-y survivors in the N + I + C arm, 21/48 (44%) received ≥ 17 doses of ipilimumab; of those who received < 17 doses, most had discontinued ipilimumab due to TRAEs. The extended f/u revealed no new safety signals. Conclusions: 1L N + I + C maintained long-term, durable survival benefit vs C in pts with mNSCLC at this 5-y f/u, particularly in pts with tumor PD-L1 expression < 1% or squamous (SQ) histology. N + I + C increased 5-y survivorship, with improved PFS and TFI in 5-y survivors over C. These data further underscore 1L N + I + C as an efficacious tx option for pts with mNSCLC. Clinical trial information: NCT03215706 . [Table: see text]