Successful Conversion Surgery after Ceritinib Monotherapy in a Patient with Advanced Inflammatory Myofibroblastic Tumor Harboring SQSTM1-ALK fusion

Inflammatory myofibroblastic tumor (IMT) is an intermediate malignant neoplasm, and approximately 50% of patients are anaplastic lymphoma kinase positive (ALK + ). Given this unique trait, ALK tyrosine kinase inhibitors (TKIs), initially developed for ALK + nonsmall cell lung carcinoma, were expected to be effective. Subsequently, crizotinib, a first-generation ALK-TKI, was approved by the U. S. Food and Drug Administration, and other generations of ALK-TKIs have since been tested for their efficacy. In this study, we report a case of unresectable IMT who showed a partial response to ceritinib, a second-generation ALK-TKI, allowing conversion surgery to be performed. Furthermore, the patient was found to have a rare ALK translocation, sequestosome 1 (5)-ALK (20), detected by next-generation sequencing. In conclusion, this case presents real-world evidence to establish the role of ceritinib as a first-line treatment for ALK + IMT, which can contribute to further studies on ALK + IMT.