Novel HIVEP1-ALK fusion in a patient with lung adenocarcinoma demonstrating sensitivity to alectinib: a case report

Background: Anaplastic lymphoma kinase (ALK) fusion is an important oncogenic driver in non-small cell lung cancer (NSCLC). Reports on the intergenic region (IGR) as an ALK fusion partner are rare. Here, we report the case of a patient with advanced NSCLC harboring a human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1)-ALK fusion that responded effectively to alectinib. Case Description: A 60-year-old non-smoking male was referred with a 3-month history of productive cough secondary to lung adenocarcinoma metastatic to mediastinal lymph nodes, brain, liver, and bone (T2N3M1c, stage IVB). Next-generation sequencing identified an IGR (upstream HIVEP1-) ALK fusion, and immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) results were consistent with an ALK-positive tumor. The patient was subsequently started on alectinib, with no obvious adverse reaction. After 1 month of therapy, the patient achieved significantly remission of the clinical symptoms and had led to an ongoing partial response (PR) lasting >33 months. Conclusions: Our experience highlights the efficacy of alectinib in a patient with HIVEP1-ALK fusion positive NSCLC with multiple metastases including brain disease, and the need for multiple genetic testing methods to verify the oncogenicity of ALK fusions prior to treatment. It could provide useful guidance for the treatment of similar cases in the future.