Efficacy analysis of ALK inhibitors for treating lung squamous carcinoma patients harboring ALK rearrangement.

Background: Anaplastic lymphoma kinase (ALK)-rearranged pulmonary squamous cell carcinoma (SCC) is a rare subtype of non-small cell lung cancer and the treatment options are limited. We aimed to evaluate the efficacy of ALK tyrosine kinase inhibitors (TKIs) in advanced lung SCC patients with ALK rearrangement.

Methods: We collected 11 primary lung SCC samples at the Zhejiang Cancer Hospital between March 2015 and October 2022. In addition, we conducted a literature search of previous studies, and a pooled analysis of 34 patients was performed. The Kaplan-Meier method was applied to generate progression-free survival (PFS) and overall survival (OS) curves, and a log-rank test was used to compare PFS and OS curves for different subgroups.

Results: A pooled analysis of 36 patients was performed. Nineteen patients (52.8%) achieved partial response and 9 (25.0%) had stable disease. The objective response rate was 52.8%, and the disease control rate was 77.8%. The median PFS was 7.10 months. Further, alectinib was not superior to crizotinib in prolonging PFS (9.00 vs. 6.00 months, P=0.60). The median PFS of patients receiving initial ALK TKIs as the first-line therapy and second- or further-line therapy was 9.00 and 6.00 months (P=0.26), respectively.

Conclusions: Patients with ALK-rearranged lung SCC obtained moderate benefit from ALK-inhibitor therapy. Compared with crizotinib, alectinib did not show superior efficacy in the treatment of ALK-positive lung SCC. Further high-quality trials are warranted.