Sintilimab Plus Platinum and Gemcitabine as First-Line Treatment for Advanced or Metastatic Squamous NSCLC: Results From a Randomized, Double-Blind, Phase 3 Trial (ORIENT-12)

Introduction: The standard chemotherapy for squamous NSCLC (sqNSCLC) includes platinum plus gemcitabine. Sintilimab, an anti-programmed cell death protein 1 antibody, plus platinum and gemcitabine (GP) has revealed encouraging efficacy as first-line therapy for sqNSCLC in a phase 1b study. We conducted a randomized, double-blind, phase 3 study to further compare the efficacy and safety of sintilimab with placebo, both in combination with GP. Methods: ORIENT-12, a randomized, double-blind, phase 3 study, was conducted at 42 centers in the People's Republic of China (ClinicalTrials.gov, number NCT03629925). Patients with locally advanced or metastatic sqNSCLC and without EGFR-sensitive mutations or ALK rearrangements were enrolled in the study. The stratification factors included clinical stage, choice of platinum, and programmed death-ligand 1 tumor proportion score. The patients, investigators, research staff, and sponsor team were masked to treatment assignment. Eligible patients were randomized 1:1, using an integrated web-response system, to receive sintilimab 200 mg or placebo plus GP every 3 weeks for four or six cycles, followed by sintilimab or placebo as maintenance therapy until disease progression or 2 years. The primary end point was progression-free survival (PFS), assessed by an independent radiographic review committee. Results: Between September 25, 2018 and July 26, 2019, a total of 543 patients were screened, of whom 357 patients were randomized to the sintilimab-GP group (n = 179) and the placebo-GP group (n = 178). After a median follow-up period of 12.9 months, sintilimab-GP continued to reveal a meaningful improvement in PFS than placebo-GP (hazard ratio = 0.536 [95% confidence interval: 0.422-0.681], p < 0.00001). Treatment-emergent adverse events of grade 3 or worse occurred in 86.6% patients in the sintilimab-GP group and in 83.1% in the placebo-GP group. The incidence of treatment-emergent adverse event leading to death was 4.5% and 6.7% in the two treatment groups, respectively. Conclusions: Regarding PFS, sintilimab plus GP reveals clinical benefit than GP alone as first-line therapy in patients with locally advanced or metastatic sqNSCLC. The toxicity was acceptable, and no new unexpected safety signals were observed. (c) 2021 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Automated summary

A randomized, double-blind, phase 3 study found that Sintilimab plus GP showed better progression-free survival compared to GP alone in first-line treatment for patients with locally advanced or metastatic sqNSCLC. The toxicity of the treatment was acceptable, and no new unexpected safety signals were observed.