Effect of alectinib versus crizotinib on progression-free survival, central nervous system efficacy and adverse events in ALK-positive non-small cell lung cancer: a systematic review and meta-analysis

Lung cancer is the most common malignant tumor, and it remains the major cause of cancerrelated death worldwide. Anaplastic lymphoma kinase fusion gene-rearrangement (ALK-positive) nonsmall cell lung cancer (NSCLC) is a unique subgroup that accounts for 3-7% of NSCLC cases. Over the last few years, the introduction of several ALK inhibitors has completely altered the treatment of advanced ALK-positive NSCLC and significantly improved the prognosis for patients. Crizotinib was the first ALK inhibitor developed, and it has demonstrated systemic efficacy and strongly improved outcomes in NSCLC patients with ALK-positive when compared with chemotherapy. Alectinib was designed specifically to be a more potent and selective anti-ALK therapeutic agent that could bypass crizotinib resistance. This study aims to evaluate the different efficacies of alectinib and crizotinib on progression-free survival (PFS), central nervous system (CNS) progression and adverse events (AEs) in NSCLC patients with ALK-positive.