Primary Resistance Mechanisms of ALK TKIs

Anaplastic lymphoma kinase (ALK) gene rearrangement is a known oncogenic driver in non-small cell lung cancer (NSCLC). ALK tyrosine kinase inhibitors (TKIs) have been clearly shown to produce excellent therapeutic effects and prolong survival in patients with this gene mutation. According to current treatment guidelines, ALK inhibitors are the first-line treatment of choice for ALK-positive advanced NSCLC patients. However, although ALK TKIs are very effective, there is still a small group of patients who do not achieve good treatment outcomes, developing resistance and tumor progression within 3 to 6 months of initial ALK TKI use. This is called primary resistance. Intrinsic resistance to ALK inhibition occurs when the best clinical response after first-generation and second/third-generation TKI treatment is disease progression. Approximately 5-7% of cases after crizotinib treatment, 9% after ceritinib treatment, and 25% after lorlatinib treatment show no response to treatment, and no specific ALK mutation has been found to explain the occurrence of primary resistance. Currently, many different resistance mechanisms are known, some of which are still ALK-related, while others are ALK-independent alternative survival pathways. However, most research focuses on acquired resistance, with very few studies on primary resistance, only a few case reports. Therefore, this study aims to explore the primary ALK TKI resistance mechanisms. The investigators plan to explore the incidence and mechanisms of primary ALK TKI resistance in ALK-positive advanced NSCLC patients who develop primary resistance or rapid progression (within 3-6 months) during ALK inhibitor treatment by re-obtaining tumor samples for genetic analysis.