Treatment of Resistant TPM3::ALK + Fusion Protein Metastatic Inflammatory Myofibroblastic Tumor with ALK Targeting and Immune Checkpoint Inhibitor Combined Therapy

Background and Clinical Significance: Inflammatory myofibroblastic tumors (IMTs) are rare neoplasms with low metastatic potential but a high recurrence rate. Approximately 60–80% of IMTs harbor anaplastic lymphoma kinase (ALK) gene rearrangements, making ALK inhibitors (ALKis) a key therapeutic option. However, resistance to ALKis remains a significant clinical challenge, necessitating alternative treatment strategies. Case Presentation: We report the case of a 23-year-old woman diagnosed with a metastatic TPM3::ALK fusion-positive IMT, initially managed with crizotinib and ceritinib. Disease progression prompted a switch to alectinib, followed by lorlatinib in combination with immune checkpoint inhibitors (nivolumab + ipilimumab). The patient tolerated this regimen well, with manageable side effects, and has remained progression-free for over three years, demonstrating the potential efficacy of ALK-ICI combination therapy. Conclusions: This case highlights the rapid development of resistance to first- and second-generation ALKis and the emerging role of immune checkpoint inhibitors (ICIs) in IMT treatment. PD-L1 expression in ALK-positive IMTs suggests an immune escape mechanism, supporting combination ALK-ICI therapy as a viable approach. The successful long-term disease control achieved in this case underscores the importance of molecular profiling in guiding personalized treatment strategies for IMT. This report contributes to the growing body of evidence supporting precision medicine and immunotherapy in rare sarcomas.