Tislelizumab plus chemotherapy as first-line treatment of locally advanced or metastatic nonsquamous non-small-cell lung cancer (final analysis of RATIONALE-304: a randomized phase III trial)
Shuaiji Lu, Jiarui Wang, Yan Yu, Xiaohua Yu, Yi Hu, Z. Ma, Xiaoling Li, Wei He, Yu‐Qing Bao, Meng Wang
Abstract
Background The purpose of this study was to report an updated, final analysis with longer follow-up for the open-label phase III RATIONALE-304 study of first-line tislelizumab plus chemotherapy versus chemotherapy alone for advanced nonsquamous non-small-cell lung cancer (nsq-NSCLC). Materials and methods Patients with histologically confirmed stage IIIB/IV nsq-NSCLC were randomized (2 : 1) to 4-6 cycles of tislelizumab plus platinum-based chemotherapy and pemetrexed every 3 weeks, followed by maintenance tislelizumab and pemetrexed, or platinum-based chemotherapy and pemetrexed alone every 3 weeks followed by maintenance pemetrexed. The primary endpoint was independent review committee (IRC)-assessed progression-free survival (PFS IRC ). Overall survival (OS), safety, and tolerability were secondary endpoints. Results Overall, 334 patients were randomized (tislelizumab plus chemotherapy: n = 223; chemotherapy: n = 111). At final analysis (median follow-up 16.1 months), safety/tolerability profiles in both arms were consistent with the interim analysis. Tislelizumab plus chemotherapy continued to demonstrate prolongation of PFS IRC versus chemotherapy alone {stratified hazard ratio (HR) 0.63 [95% confidence interval (CI) 0.47-0.86]; median PFS IRC 9.8 months (95% CI 8.9-11.7 months) versus 7.6 months (95% CI 5.6-8.0 months), respectively}. OS stratified HR for tislelizumab plus chemotherapy versus chemotherapy was 0.90 (95% CI 0.63-1.28), with median OS of 21.4 months (95% CI 17.7 months-not estimable) versus 21.3 months (95% CI 15.6 months-not estimable), respectively. At a subsequent ad hoc analysis (median follow-up 19.3 months), OS HR between arms was 0.85 (95% CI 0.63-1.14); when adjusted for crossover using the two-stage method, the OS HR was 0.68 (95% CI 0.48-0.96). Conclusions After longer follow-up, first-line tislelizumab plus chemotherapy continued to demonstrate a manageable safety profile and a favorable PFS benefit over chemotherapy alone in patients with advanced/metastatic nsq-NSCLC.