Ensartinib treatment for REV1-ALK/EML4-ALK complex ALK fusion lung adenocarcinoma:a case report

ZHANG Chang-gong

doi:10.20251/j.cnki.1003-3734.2025.05.007

Abstract：Anaplastic lymphoma kinase(ALK)positivity is one of the important molecular subtypes in non-small cell lung cancer(NSCLC).Reports of compound ALK fusions are relatively uncommon in clinical practice,especially given the widespread clinical application of new second-and third-generation ALK tyrosine kinase inhibitors(TKIs).These new-type of TKIs have demonstrated superior efficacy and enhanced central nervous system(CNS)penetration compared to traditional chemotherapy and first-generation TKIs,establishing themselves as an important treatment option for patients with advanced ALK-positive NSCLC.However,the efficacy and outcomes associated with these drugs,particularly in patients harboring rare compound ALK fusions,still require further research to guide the clinical treatment.In the current case,we described a 52-year-old male patient diagnosed with lung adenocarcinoma who carried both a novel REV1-ALK fusion and an EML4-ALK fusion,a combination that is relatively rare in clinical practice.The implications of this dual fusion on treatment response and prognosis remain inadequately understood.The patient was administered ensartinib,a domestic,second-generation ALK inhibitor that competitively inhibits ATP binding to ALK,blocking the phosphorylation process of tyrosine kinase,thereby inhibiting the growth and proliferation of cancer cells.The patient exhibited a rapid response to the treatment,achieving sustained partial response over the duration of medication exceeding 10 months.The outcome suggests that ensartinib may offer promising efficacy for cases involving rare compound ALK fusions.This case provides valuable experience for the treatment of rare compound ALK fusion cases and may assist in guiding future treatment decisions.