Outcomes of sintilimab plus pemetrexed and platinum (SPP) according to stage of disease in patients (pts) with locally advanced or metastatic nonsquamous NSCLC (AMnsqNSCLC) in the phase 3 ORIENT-11 study.

e21157 Background: In ORIENT-11, first-line (1L) SPP improved progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and duration of response (DoR) compared with placebo plus pemetrexed-platinum (PPP) in pts with AMnsqNSCLC. We report outcomes from ORIENT-11 (NCT03607539) for pts treated with SPP with stage III (b & c) compared with stage IV disease. Methods: Pts with treatment-naïve locally AMnsqNSCLC without sensitizing EGFR/ALK alterations were randomly assigned to SPP (n = 266) or PPP (n = 131), stratified by PD-L1 expression, platinum-chemotherapy and sex. Primary endpoint was PFS (RECIST v1.1). Secondary endpoints included OS, ORR, DoR and safety. Kaplan-Meier method was used to analyze median PFS, OS and DoR. Stratified Cox model was used to analyze the hazard ratio (HR) of SPP vs. PPP. Clopper-Pearson method was used to calculate the 95% confidence intervals (CI) of ORR for each group. Miettinen-Nurminen method was used to analyze 95% CI of ORR difference between SPP and PPP. Data cutoff for OS data was September 15, 2021, providing a median follow-up of 30.8 months. Cutoff for other data was November 15, 2019, providing a median follow-up of 8.9 months. Results: 21 pts (7.9%) receiving SPP had stage III disease and 245 pts (92.1%) had stage IV disease. Baseline sex, age and PD-L1 expression ≥1% were similar between subgroups (Table). There were differences between subgroups in number of pts receiving carboplatin and ECOG performance status at baseline. PFS, OS, ORR and DoR outcomes were comparable between pts with stage III and stage IV disease based on the ad-hoc analyses. Any-grade adverse events (AEs) (100.0% vs. 99.6%) and AEs of Grade ≥3 (57.1% vs. 62.0%) were similar in pts with stage III and stage IV disease. Conclusions: In ORIENT-11, outcomes for pts receiving SPP as 1L therapy in AMnsqNSCLC with stage III and stage IV disease were comparable. Clinical trial information: NCT03607539. [Table: see text]