Consolidation ALK Tyrosine Kinase Inhibitors Versus Durvalumab or Observation After Chemoradiation in Unresectable Stage III ALK-Positive NSCLC

Abstract

Introduction: Patients with advanced ALK-positive NSCLC typically have poor response to immunotherapy; the benefit of consolidation durvalumab in patients with unresectable stage III ALK-positive NSCLC remains unclear. Herein, we compare the efficacy and safety of consolidation ALK tyrosine kinase inhibitor (TKI) versus durvalumab or observation after concurrent chemoradiation.

Methods: We conducted a retrospective study using a multicenter study of 17 institutions globally. Patients with unresectable stage III ALK-positive NSCLC treated between 2015 and 2022 were included. Patients received ALK TKI, durvalumab, or observation after concurrent chemoradiation. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated using Kaplan-Meier method. Treatment-related adverse events (trAEs) were classified by Common Terminology Criteria for Adverse Events version 5.0. Outcomes were assessed by multivariable Cox regression analysis.

Results: A total of 67 patients were included, of whom 39 (58%) were female. Median age was 57 (interquartile range: 49-67) years. Furthermore, 15 received consolidation ALK TKI, 30 received durvalumab, and 22 underwent observation. Baseline characteristics were similar across the three groups other than differences in race. After adjusting for stage, age, and nodal status, median rwPFS was significantly longer for ALK TKI (rwPFS not reached, 95% confidence interval [CI]: 22.7- not reached) versus durvalumab (11.3 mo, 95% CI: 8.9-18.5, hazard ratio [HR] = 0.12, 95% CI: 0.026-0.5, p-adjusted [p-adj] = 0.006) or observation (7.2 mo, 95% CI: 3.4-10.6, HR = 0.04, 95% CI: 0.009-0.2, p-adj < 0.0001). Durvalumab significantly improved median rwPFS compared with observation (HR = 0.37, 95% CI: 0.19-0.71, p-adj = 0.002). Median OS in the ALK TKI and durvalumab cohorts was significantly improved compared with patients on observation (ALK TKI-observation: p = 0.04; durvalumab-observation: p = 0.03). TrAE of any grade occurred in eight (53%) and 11 (37%) patients treated with ALK TKI and durvalumab, respectively. Grade greater than or equal to three trAEs occurred in 27% (n = 4) of patients treated with ALK TKI and 6.7% of patients treated with durvalumab.

Conclusions: Patients with ALK-positive NSCLC experience significantly improved rwPFS when treated with consolidation ALK TKI therapy, surpassing outcomes found with either durvalumab or observation. Although both ALK TKI therapy and durvalumab offer an extension in OS compared with observation alone, it seems that ALK TKI therapy is the superior choice, underscoring its pivotal role in enhancing patient survival.

Keywords: ALK inhibitors; Chemoradiation; Immunotherapy; Non–small cell lung cancer.