Abstract CT041: ORIENT-3: A randomized, open-label, phase 3 study of sintilimab versus docetaxel in previously treated advanced/metastatic squamous non-small-cell lung cancer (sqNSCLC)

Abstract

Abstract Background: Patients (pts) with advanced squamous NSCLC (sqNSCLC) have very limited second-line treatment options after failure of the platinum-based doublet chemotherapy. ORIENT-3 was conducted to compare the efficacy and safety of sintilimab, an anti-PD-1 antibody, with docetaxel in second-line treatment in sqNSCLC. (NCT03150875) Method: Pts with stage IIIB/IIIC or IV (ineligible for radical chemo-radiotherapy) sqNSCLC who have disease progression during or after first-line platimum-based chemotherapy were enrolled and randomized 1:1 to receive sintilimab 200mg (Sin arm) or docetaxel 75mg/m2 (Doc arm) intravenously, Q3W until disease progression or intolerable toxicity. Stratification factor was ECOG score (0 vs. 1). The primary endpoint was overall survival (OS). Results: As of July 31, 2020, 290 pts were enrolled with 145 in each treatment group. Efficacy analysis was based on FAS (n=280), and safety analysis was based on safety set (n=274). Baseline characteristics were well balanced between treatment groups, and most pts in efficacy analysis (75.9% in Sin arm, 77.0% in Doc arm) had ECOG PS score of 1. Pts received a median of 8.0 cycles (range: 1-45) of sintilimab, and 2.0 cycles of docetaxel (range: 1-15). With a median follow-up of 23.56 months, sintilimab had a significant improvement in OS versus docetaxel (median: 11.79 m [95% CI 10.28-15.57] vs. 8.25 m [95% CI 6.47-9.82]; HR 0.74, [95%CI 0.56-0.96], P = 0.02489). The median PFS was also significantly superior in Sin arm (4.30 m, 95% CI 4.04-5.78) to that in Doc arm (2.79 m, 95% CI 1.91-3.19) (HR 0.52, 95% CI 0.39-0.68, P<0.00001). The confirmed ORR was 25.5% (95% CI, 18.6%-33.4%) in Sin arm and 2.2% (95% CI 0.5%-6.4%) in Doc arm. 84.7% of pts in Sin arm and 83.1% in Doc arm reported treatment-related adverse events (TRAEs), most commonly with hypothyroidism (18.1%) and alopecia (34.6%), respectively. TRAEs ≥ grade 3 were less frequent in Sin arm (18.1%) than in Doc arm (36.2%). Five pts occurred sintilimab-related death, and one death reported relating with docetaxel. Conclusion: Sintilimab as second-line treatment for advanced and metastatic sqNSCLC showed a superior OS and PFS benefit, compared with docetaxel. Citation Format: Yuankai Shi, Lin Wu, Xinmin Yu, Yan Wang, Puyuan Xing, Jianying Zhou, Airong Wang, Jianhua Shi, Yi Hu, Ziping Wang, Guangyu An, Yong Fang, Sanyuan Sun, Caicun Zhou, Changli Wang, Feng Ye, Xingya Li, Junye Wang, Mengzhao Wang, Yunpeng Liu, Yanqiu Zhao, Jifeng Feng. ORIENT-3: A randomized, open-label, phase 3 study of sintilimab versus docetaxel in previously treated advanced/metastatic squamous non-small-cell lung cancer (sqNSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT041.