Alectinib treatment response in lung adenocarcinoma patient with novel EML4‐ALK variant

Common gene fusion of the ALK gene is fusion of the ALK tyrosine kinase area and the 5’end of EML4. Seventeen EML4‐ALK fusion variants have been reported. Herein, we report a novel EML4‐ALK variant detected by next‐generation sequencing in a 36‐year‐old female lung adenocarcinoma patient who experienced disease progression after six months of alectinib treatment. Second generation sequencing revealed an EML4‐ALK fusion variant in which intron 19 of EML4 was fused to exon 20 of ALK. This is the first case of EML4‐ALK (E19: A20) fusion to be reported. Alectinib may show unsatisfactory therapeutic effects for this kind of ALK fusion.