Cheng Y, Fan Y, Zhao Y, Huang D, Li X, Zhang P, Kang M, Yang N, Zhong D, Wang Z, Yu Y, Zhang Y, Zhao J, Qin T, Chen C, Leaw S, Zheng W, and Song Y
Introduction: Extensive-stage SCLC (ES-SCLC) prognosis remains poor. The phase 3 RATIONALE-312 study aimed to evaluate the efficacy and safety of tislelizumab plus chemotherapy as first-line treatment for ES-SCLC., Methods: RATIONALE-312 is a randomized, double-blind, placebo-controlled trial, conducted in the People's Republic of China. Eligible patients with previously untreated ES-SCLC were randomized 1:1 to receive four cycles of tislelizumab 200 mg or placebo, with etoposide plus carboplatin or cisplatin intravenously every 3 weeks, followed by tislelizumab 200 mg or placebo as maintenance. The primary end point was overall survival (OS). Secondary end points included progression-free survival and safety., Results: Between July 22, 2019 and April 21, 2021, 457 patients were randomized to tislelizumab (n = 227) or placebo (n = 230), plus chemotherapy. Baseline demographics were generally balanced between arms. At the data cutoff (April 19, 2023), the median study follow-up was 14.2 months (interquartile range: 8.6-25.3). Tislelizumab plus chemotherapy exhibited a statistically significant OS benefit versus placebo plus chemotherapy (stratified hazard ratio = 0.75 [95% confidence interval (CI): 0.61-0.93]; one-sided p = 0.0040; median: 15.5 [95% CI: 13.5-17.1] versus 13.5 mo [95% CI: 12.1-14.9], respectively). Progression-free survival was significantly improved in the tislelizumab versus placebo arm (stratified hazard ratio = 0.64 [95% CI: 0.52-0.78]; p < 0.0001; median: 4.7 [95% CI: 4.3-5.5] versus 4.3 mo [95% CI: 4.2-4.4], respectively). Grade greater than or equal to 3 treatment-related adverse events were reported in 86% of patients in each treatment arm and were mostly hematologic., Conclusions: Tislelizumab plus chemotherapy exhibited statistically significant clinical benefit and manageable safety compared with placebo plus chemotherapy as first-line treatment in patients with advanced ES-SCLC., Competing Interests: Disclosure Dr. Zhao reports receiving payment or honoraria for lectures, presentations, speaker bureaus, manuscript writing, or educational events from Roche, AstraZeneca, Merck Sharp & Dohme, Novartis, and Eli Lilly. Drs. Qin and Zheng are employees of BeiGene (Beijing) Co., Ltd. and have stock or stock options with BeiGene (Beijing) Co., Ltd. Dr. Leaw and Ms. Chen are employees of BeiGene (Shanghai) Co., Ltd. and have stock or stock options with BeiGene (Shanghai) Co., Ltd. The remaining authors declare no conflict of interest., (Copyright © 2024 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)