Tislelizumab Plus Platinum and Etoposide Versus Placebo Plus Platinum and Etoposide as First-Line Treatment for Extensive-Stage SCLC (RATIONALE-312): A Multicenter, Double-Blind, Placebo-Controlled, Randomized, Phase 3 Clinical Trial.

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.

Real-world evaluation of first-line treatment of extensive-stage small-cell lung cancer with atezolizumab plus platinum/etoposide: a focus on patients with brain metastasis.

PURPOSE: A previous real-world study conducted in China confirmed that first-line atezolizumab, in combination with etoposide/platinum (EP), leads to significantly longer progression-free survival (PFS) compared to EP alone in patients with extensive-stage small-cell lung cancer (ES-SCLC). The present study aimed to provide updated survival outcome data and evaluate the clinical efficacy of atezolizumab plus chemotherapy in ES-SCLC patients with brain metastasis (BM). METHODS: This retrospective study included 225 patients with ES-SCLC who were treated with EP alone (EP group) or a combination of EP + atezolizumab (atezolizumab group). Survival outcomes for the total study sample and patients in the BM subgroup were estimated using the Kaplan-Meier method. RESULTS: The atezolizumab group continued to demonstrate significantly longer PFS than the EP group (hazard ratio [HR], 0.68). The median overall survival (OS) was 26.2 months in the atezolizumab group vs. 14.8 months in the EP group (HR, 0.63). Additionally, among the BM patients in our study, the median PFS was found to be longer in the atezolizumab group (7.0 months) than in the EP group (4.1 months) (HR, 0.46). The OS of the BM patients did not differ significantly between the two treatment groups. CONCLUSIONS: The addition of atezolizumab to EP as a first-line treatment for ES-SCLC was found to improve survival outcomes. This treatment combination may also prolong PFS in patients with BM, regardless of the administration of cranial irradiation. However, among the BM patients in our study, there was no significant difference in OS between the two treatment groups.