Final overall survival data of sintilimab plus pemetrexed and platinum as First-Line treatment for locally advanced or metastatic nonsquamous NSCLC in the Phase 3 ORIENT-11 study

Objectives: In ORIENT-11, first-line sintilimab + pemetrexed-platinum significantly improved PFS compared with placebo + pemetrexed-platinum in patients with advanced metastatic nonsquamous non-small-cell lung cancer (AMnsqNSCLC). The study met the primary endpoint of PFS as of 15November2019. Here we report final survival analysis from ORIENT-11 (NCT03607539) using a 15September2021 data cutoff. Methods: Patients with treatment-naive locally AMnsqNSCLC without sensitizing EGFR or ALK genomic tumor aberrations were randomly assigned to sintilimab + pemetrexed-platinum (n = 266) or placebo + pemetrexed-platinum (n = 131). Patients were stratified by PD-L1 expression, platinum-chemotherapy, and gender. Treatment continued until PD, unacceptable toxicity, or a maximum of 24 months. Patients in the placebo + pemetrexed-platinum arm could be sequenced to second-line sintilimab monotherapy, contingent upon PD. Response was assessed (RECISTv.1.1) by blinded independent radiographic review committee. Primary endpoint was PFS. OS was a secondary endpoint and defined from date of randomization to date of death due to any cause. Final OS analysis was defined as approximately 2 years after last patient randomized or when approximately 65 % of patients died, whichever first. Results: At data cutoff of final OS analysis, median study follow-up was 30.8 months. Of 397 patients, 243 OS events were observed (sintilimab + pemetrexed-platinum:151[57 %];placebo + pemetrexed-platinum:92 [70 %]). Of the patients in placebo + pemetrexed-platinum arm, 47 % crossed over to sintilimab monotherapy per protocol. Median OS was 24.2 months in sintilimab + pemetrexed-platinum arm and 16.8 months in placebo + pemetrexed-platinum arm (HR:0.65[95 % CI:0.50,0.85]). Estimated 2-year OS rates were 50 %(sintilimab + pemetrexed-platinum) and 32 %(placebo + pemetrexed-platinum). After adjusting for the crossover effect, OS treatment effect was more pronounced with HR 0.52 (95 % CI:0.38,0.69). OS benefit across all prespecified subgroups was largely consistent with that observed in the ITT population. Conclusions: In the ORIENT-11 final OS analysis, sintilimab + pemetrexed-platinum demonstrated improved OS compared to placebo + pemetrexed-platinum when administered as first-line therapy in AMnsqNSCLC without EGFR or ALK genomic tumor aberrations.