Analysis of Baseline Molecular Factors Associated With the Risk of Central Nervous System Progression Among Alectinib-Treated Patients With ALK-Positive NSCLC.

Introduction: Despite receiving alectinib therapy, patients with ALK-positive NSCLC remain at risk of central nervous system (CNS) progression. Our retrospective study aimed to identify baseline clinical and molecular factors associated with the risk of CNS progression in this patient subset.

Methods: We analyzed the clinical, molecular, and imaging data of 318 patients with ALK-positive advanced NSCLC who received alectinib as first-line (1L-alectinib) or second-line (2L-alectinib) therapy at baseline (1L, n = 183; 2L, n = 135) and at disease progression (1L, n = 80; 2L, n = 76).

Results: The incidence rates of CNS progression were 23.7% after 1L-alectinib treatment and 31.6% after 2L-alectinib treatment. Compared with patients who received 1L-alectinib, CNS progression was similar in patients who received 2L-alectinib ( > 0.05). Oligoprogression was detected in 55.0% (44 of 80) of patients who progressed after first-line alectinib, with the remaining 45.0% (36 of 80) having nonoligoprogression. Univariate and multivariate analyses and stepwise regression analyses consistently identified a higher likelihood of CNS progression among (1) patients who received 2L-alectinib than 1L-alectinib, (2) patients with non-3a/b variant fusion than those with echinoderm microtubule-associated protein-like 4 variant 3a/b, and (3) patients with programmed death ligand 1 (PD-L1) tumor proportion score (TPS) of 50% or higher than PD-L1 TPS of less than 50%.

Conclusions: Our study provided real-world evidence that patients who harbored PD-L1 TPS of 50% or higher were more likely to experience CNS progression during alectinib therapy. The association between CNS progression and breakpoint variants warrants further investigation. Our findings suggest that close monitoring and prompt intervention are crucial in prolonging the quality of life of this patient subset.