Transportability of tislelizumab trial outcomes from RATIONALE-315, RATIONALE-303, and RATIONALE-312 to the European population in early-stage non-small cell lung cancer (NSCLC), advanced NSCLC and extensive-stage small cell lung cancer (ES-SCLC).

Abstract

Background: Tislelizumab was evaluated in randomized controlled trials (RCTs) for non-small cell lung cancer (NSCLC) (RATIONALE-315, RATIONALE-303) and extensive-stage small cell lung cancer (ES-SCLC) (RATIONALE-312), primarily in Asian populations. We assessed the transportability of clinical findings from these RCTs to European patients.

Methods: Targeted literature reviews (TLRs) identified real world-evidence (RWE), RCTs, and treatment effect modifiers in perioperative NSCLC, second-line or later (2L+) NSCLC, and first-line (1L) ES-SCLC. Relevant RWE studies were selected to define the target European-like populations. Outcome regression models used RATIONALE individual patient data to predict relative treatment effect of tislelizumab vs. comparators in European populations.

Results: Event-free survival (HR 0.56), major pathological response (OR 7.49) and pathological complete response (OR 11.54) from RATIONALE-315 were similar to those predicted for the base case European target perioperative NSCLC population (EFS HR 0.57; MPR OR 3.39; PCR OR 8.95). Predicted overall survival and progression-free survival for 2L+ NSCLC and for 1L ES-SCLC were similar to RATIONALE-303 and RATIONALE-312, respectively.

Conclusion: The efficacy of tislelizumab observed in the RATIONALE trials explored in this analysis is transportable, subject to the specified assumptions, to European patients in the setting of perioperative NSCLC, 2L+ NSCLC, and 1L ES-SCLC, consistently favoring tislelizumab over control.